996 Carrera 4S (2002-2005) Exhaust
996 Carrera 4S (2002-2005) Exhaust
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Product Description
The SOUL Sport Catalytic Converters are a direct-fit performance upgrade for the 1999–2004 Porsche 996 Carrera, replacing the restrictive factory catalyst assemblies with freer-flowing high-flow catalytic converters designed to increase exhaust flow, improve performance potential, and bring significantly more character out of Porsche's naturally aspirated flat-six.
SOUL took a particularly sound-focused approach to the 996. Rather than connecting the left and right cylinder banks through an X-pipe, SOUL deliberately keeps the exhaust banks separated after testing both configurations back-to-back. SOUL found that an X-pipe reduced some of the deeper frequencies that give the 996 its distinctive sound, while the split-bank configuration produced a deeper, fuller flat-six note with greater volume and a slight rasp reminiscent of earlier air-cooled Porsche exhaust character.
The complete SOUL assemblies weigh approximately 13 lbs compared with 15 lbs for the factory catalyst components, reducing exhaust-system weight by approximately 2 lbs / 0.9 kg.
SOUL also developed the Sport Catalytic Converters around increased flow without catalyst-related check engine lights under normal operation, making them a much more street-oriented alternative to completely catless bypass pipes.
FITMENT:
Fits 1999–2004 Porsche 996 Carrera
Fits 1999–2004 Porsche 996 Carrera Cabriolet
Fits 1999–2004 Porsche 996 Carrera 4
Fits 1999–2004 Porsche 996 Carrera 4 Cabriolet
Fits 2002–2004 Porsche 996 Carrera 4S
Fits 2004 Porsche 996 Carrera 4S Cabriolet
SOUL specifies fitment for all Porsche 996 Carreras from 1999–2004
Compatible with 996.1 and 996.2 Carrera applications
Compatible with the factory rear mufflers
Compatible with SOUL Sport Side Mufflers
Compatible with other appropriate 996 Carrera rear exhaust configurations
Does not apply to 996 Turbo, GT2, or GT3 models
DETAILS:
Pair of Sport Catalytic Converter assemblies
Premium high-flow catalytic converters
Replaces the restrictive factory catalyst assemblies
Retains a catted exhaust configuration
Designed to improve exhaust flow
Designed to increase performance potential
Increased flat-six exhaust volume
Deeper, fuller naturally aspirated exhaust tone
Slightly more aggressive rasp
Air-cooled-inspired tonal character
Split-bank exhaust design
Deliberately avoids an X-pipe in the catalyst section
SOUL tested split-bank and X-pipe configurations back-to-back
Developed for catalyst-related CEL-free operation under normal conditions
Approximately 13 lbs / 5.9 kg
Factory catalyst assemblies approximately 15 lbs / 6.8 kg
Saves approximately 2 lbs / 0.9 kg
Approximately 13% lighter than the factory components being replaced
Constructed from .065-inch-wall T304L stainless steel
Smooth mandrel-bent tubing
Thick exhaust flanges
New catalyst-to-header mounting hardware included
Fixture-tested prior to shipment
Foam-packed after quality inspection
Designed and manufactured in Willow Grove, Pennsylvania
3-year warranty on the catalytic converters
Lifetime warranty on the stainless-steel pipe assemblies
HIGH-FLOW CATALYTIC CONVERTERS
The factory 996 Carrera catalytic converters are one of the more restrictive components in the original exhaust system.
SOUL replaces the original assemblies with freer-flowing catalytic converters designed to increase exhaust-flow capacity while retaining catalyst functionality.
Benefits include:
Reduced exhaust restriction
Greater exhaust sound
Increased engine character
Improved performance potential
Retained catalytic converters
Reduced diagnostic compromise compared with fully catless pipes
DEVELOPED SPECIFICALLY AROUND 996 SOUND
The development of these Sport Catalytic Converters was not simply a matter of fitting a less restrictive catalyst into the factory location.
SOUL tested different exhaust architectures to determine how the catalyst section affected the distinctive character of the 996 flat-six.
One of the most important findings involved the relationship between the two cylinder banks.
SPLIT-BANK DESIGN
SOUL ultimately chose to keep the left and right exhaust banks separate through the catalyst section.
This was an intentional acoustic decision.
The split-bank configuration helps preserve:
Deeper exhaust frequencies
Fuller flat-six tone
Greater exhaust volume
Individual cylinder-bank character
A slightly rawer and more mechanical sound
The result is particularly appropriate for the naturally aspirated 996 Carrera, where exhaust tone and engine character are often as important as outright volume.
WHY SOUL DID NOT USE AN X-PIPE
SOUL also tested an X-pipe arrangement during development.
The company found that connecting the two banks through an X-pipe produced a hollower exhaust note and removed some of the deeper frequencies it preferred on the 996.
SOUL therefore chose the split-bank architecture for the production system.
This is an important distinction from many performance exhaust systems where an X-pipe is automatically assumed to be the desirable solution.
On the 996, SOUL prioritized the sound character produced by keeping the banks separated.
DEEPER, FULLER FLAT-SIX SOUND
SOUL describes the finished sound as deeper and fuller than the factory catalyst configuration.
Expect greater:
Flat-six mechanical character
Midrange exhaust presence
High-RPM intensity
Throttle-related feedback
Acceleration volume
Exhaust texture
The high-flow catalyst configuration also introduces a subtle additional rasp without turning the system into an uncontrolled or excessively harsh catless exhaust.
AIR-COOLED-INSPIRED CHARACTER
One of SOUL's development goals was to bring some of the rawer character associated with earlier Porsche flat-six engines into the water-cooled 996 platform.
The combination of:
Separate exhaust banks
Freer-flowing catalysts
Reduced sound attenuation
produces a tone SOUL characterizes as having a hint of air-cooled-inspired exhaust character.
This does not make a 996 sound identical to an air-cooled 911, but it describes the deeper and more mechanical direction SOUL pursued during development.
WITH FACTORY SIDE MUFFLERS
The Sport Catalytic Converters can be installed while retaining the factory Porsche rear mufflers.
This is the more conservative configuration.
Expect:
Increased engine sound
Deeper exhaust tone
Greater throttle-related character
Improved exhaust flow
Retained factory rear mufflers
Retained OEM exterior appearance
More restrained overall volume than a complete aftermarket exhaust system
For a street-driven 996, this provides a useful first-stage exhaust upgrade.
WITH SOUL SPORT SIDE MUFFLERS
SOUL specifically developed those mufflers with upgraded high-flow catalysts in mind.
The combination provides:
High-flow catalytic converters
Increased naturally aspirated flat-six character
Greater overall exhaust volume
Deeper tone
More aggressive high-RPM sound
SOUL's proprietary drone-control mufflers
Better cruising refinement than a muffler-delete configuration
This is the logical more-complete street exhaust setup for a 996 Carrera owner who wants increased sound without going fully catless.
WITH MORE AGGRESSIVE REAR EXHAUST COMPONENTS
Because the Sport Catalytic Converters allow more exhaust energy and sound downstream, the final character will depend heavily on the rear exhaust installed behind them.
A car using:
Factory mufflers
will remain comparatively restrained.
A car using:
SOUL Sport Side Mufflers
will become substantially more engaging while retaining acoustic control.
More aggressive muffler-bypass or race-oriented components will further increase:
Volume
Rasp
Cabin presence
High-RPM intensity
DEVELOPED FOR CEL-FREE OPERATION
SOUL currently markets the Sport Catalytic Converters around providing increased performance and sound without a check engine light.
That is an important distinction from the company's Cat Bypass Pipes.
DasMotoring should treat this as the manufacturer's design intent, not as an unconditional diagnostic guarantee on every 20+ year-old vehicle.
Catalyst-monitoring behavior can still potentially be affected by:
Aging oxygen sensors
Existing exhaust leaks
ECU software
Engine condition
Fuel mixture
Additional exhaust modifications
Catalyst condition over time
NO ECU TUNE REQUIRED
SOUL does not specify an ECU tune as necessary for installation.
The Sport Catalytic Converters are intended as a bolt-on hardware upgrade.
A performance calibration may provide additional benefit when combined with other engine modifications, but one is not required simply to install these catalyst assemblies.
NO PUBLISHED STANDALONE DYNO NUMBER
SOUL describes the high-flow catalysts as providing increased power, but the current product page does not provide a controlled factory-catalyst versus Sport-Catalyst dyno comparison.
There is no manufacturer-supported numerical horsepower or torque gain appropriate to publish for this product alone.
2-LB WEIGHT REDUCTION
SOUL publishes:
Factory Catalytic Converter Assemblies:
approximately 15 lbs / 6.8 kg
SOUL Sport Catalytic Converters:
approximately 13 lbs / 5.9 kg
Weight Savings:
approximately 2 lbs / 0.9 kg
That represents approximately a:
13% reduction
in the weight of the catalyst components being replaced.
The primary benefits of this product are flow and sound rather than substantial weight reduction, but the 2-lb reduction is still a useful secondary benefit.
.065-INCH T304L STAINLESS CONSTRUCTION
The catalyst assemblies are fabricated from:
.065-inch-wall T304L stainless steel
This provides:
High-temperature durability
Corrosion resistance
Structural strength
Long service life
Consistent exhaust fabrication
Suitability for repeated street and track heat cycles
SMOOTH MANDREL BENDS
SOUL uses smooth mandrel bends to maintain the internal cross-sectional area of the exhaust tubing through changes in direction.
This helps preserve:
Exhaust flow
Internal geometry
Consistent fitment
Structural integrity
THICK EXHAUST FLANGES
The Sport Catalytic Converters use substantial exhaust flanges to maintain proper sealing and alignment during repeated heating and cooling cycles.
This is especially important on the 996, where original exhaust hardware may already have experienced decades of heat cycling.
NEW MOUNTING HARDWARE INCLUDED
SOUL supplies new hardware for the:
Catalytic Converter → Header
connections.
This avoids relying solely on aged original mounting hardware during installation.
Additional existing exhaust hardware should still be inspected during installation and replaced where appropriate.
FIXTURE-TESTED FITMENT
Each catalyst assembly is manufactured and inspected using dedicated production fixtures.
SOUL tests the completed components for correct fitment before shipment.
This helps verify:
Flange alignment
Pipe geometry
Catalyst positioning
Downstream exhaust alignment
Overall dimensional consistency
The completed components are then foam packed for shipping.
CARRERA 4S COMPATIBILITY
Unlike the Sport Side Mufflers we just cataloged, these Sport Catalytic Converters are not limited to the narrow-body Carrera muffler architecture.
SOUL specifies the catalyst product for all 996 Carreras from 1999–2004, and the same POR.996.SCC hardware is used on Carrera 4S applications.
This means a Carrera 4S owner can use these Sport Catalytic Converters even though they need the separate C4S-specific SOUL Side Mufflers if upgrading the rear muffler section.
SPORT CATALYTIC CONVERTERS VS. CAT BYPASS PIPES
SOUL Sport Catalytic Converters
$3,055.00
Retain high-flow catalytic converters
Split-bank architecture
Deeper, fuller exhaust tone
Developed for CEL-free operation
Approximately 13 lbs
Saves approximately 2 lbs
More street-oriented configuration
SOUL Cat Bypass Pipes
Lower purchase price
Completely catless
Maximum catalyst-section flow
Greater exhaust volume
More raw exhaust character
Greater emissions implications
Catalyst-related CEL potential
Competition-oriented configuration
The Sport Catalytic Converters are the more appropriate choice for customers wanting increased sound and flow without completely removing the catalyst substrates.
CATALYTIC-CONVERTER WARRANTY
SOUL provides a specific:
3-year warranty
on the catalytic converters themselves.
The stainless-steel pipe assemblies are covered by SOUL's:
Lifetime Warranty
for street and track use.
This distinction is important because the catalyst substrates are wear and emissions-control components with different service characteristics than the fabricated stainless-steel piping.
EMISSIONS NOTE
The SOUL Sport Catalytic Converters retain catalytic converters but replace Porsche's original catalyst assemblies with aftermarket high-flow components.
Their presence should not be interpreted as guaranteeing compliance with every emissions or inspection program.
Customers are responsible for determining whether the product and their complete vehicle configuration comply with applicable regulations and inspection requirements.
Product Description
The SOUL Cat Bypass Pipes are a direct-fit, completely catless performance upgrade for the 1999–2004 Porsche 996 Carrera, replacing the restrictive factory catalytic-converter assemblies with lightweight 2.25-inch T304L stainless-steel bypass pipes.
SOUL developed these pipes with particular attention to the naturally aspirated 996's exhaust character. Rather than joining the left and right cylinder banks with an X-pipe, SOUL deliberately uses a split-bank design after back-to-back testing showed that keeping the banks separated preserved more of the deep frequencies and distinctive character of Porsche's flat-six.
The result is substantially increased exhaust volume, a deeper and fuller flat-six tone, additional rasp, improved throttle response, and a rawer exhaust character that SOUL describes as having a hint of an air-cooled Porsche sound.
At approximately 8.75 lbs, the SOUL Cat Bypass Pipes are approximately 6.25 lbs / 2.8 kg lighter than the roughly 15-lb factory catalytic-converter assemblies they replace.
FITMENT:
Fits 1999–2004 Porsche 996 911 Carrera
Fits 1999–2004 Porsche 996 911 Carrera Cabriolet
Fits 1999–2004 Porsche 996 911 Carrera 4
Fits 1999–2004 Porsche 996 911 Carrera 4 Cabriolet
Fits 2002–2004 Porsche 996 911 Carrera 4S
Fits 2004 Porsche 996 911 Carrera 4S Cabriolet
Fits 2002–2004 Porsche 996 911 Targa
Compatible with both 996.1 and 996.2 Carrera
Fits applicable 3.4L and 3.6L naturally aspirated Carrera engines
Compatible with the factory rear mufflers
Compatible with SOUL Sport Side Mufflers where applicable
Compatible with Carrera 4S-specific SOUL rear mufflers
Does not fit 996 Turbo, GT2, or GT3
DETAILS:
Pair of completely catless Cat Bypass Pipes
Replaces both factory catalytic-converter assemblies
Split-bank exhaust architecture
Left and right cylinder banks remain separated
Specifically developed after comparison testing against an X-pipe configuration
Designed for a deeper, fuller 996 flat-six exhaust tone
Increased overall exhaust volume
Additional exhaust rasp and mechanical character
Increased throttle response
Improved overall drivability
Increased performance potential
2.25-inch outside-diameter tubing
.065-inch wall thickness
T304L stainless-steel construction
Smooth mandrel bends
Thick exhaust flanges
New header-flange hardware included
Approximately 8.75 lbs / 4.0 kg
Factory components approximately 15 lbs / 6.8 kg
Saves approximately 6.25 lbs / 2.8 kg
Approximately 42% lighter than the factory catalyst assemblies
Fixture-tested prior to shipment
Foam-packed following quality inspection
May trigger a catalyst-related check engine light
Designed and manufactured in Willow Grove, Pennsylvania
No product variants
Backed by SOUL Performance Products' Lifetime Warranty for street and track use
COMPLETE CATALYTIC-CONVERTER DELETE
The SOUL Cat Bypass Pipes completely eliminate the original Porsche catalytic converters.
The factory catalysts create a significant restriction in the 996 Carrera exhaust system while also absorbing a considerable amount of the naturally aspirated flat-six's sound.
SOUL replaces these assemblies with unrestricted stainless-steel pipes.
The result provides:
Reduced exhaust restriction
Increased exhaust-flow capacity
Greater flat-six sound
Increased throttle response
Reduced exhaust-system weight
Greater performance potential
The tradeoff is that the vehicle no longer retains catalytic converters.
SPLIT-BANK EXHAUST DESIGN
One of the most interesting aspects of this product is SOUL's decision not to use an X-pipe.
The left and right cylinder-bank exhaust streams remain separate through the catalyst-replacement section.
SOUL specifically tested:
Split-Bank Pipes
against:
X-Pipe Architecture
during development.
The company ultimately preferred the sound produced by keeping the two banks independent.
WHY SOUL CHOSE SPLIT BANKS
During back-to-back testing, SOUL found that an X-pipe changed the sound of the 996 in a way it did not prefer.
The X-pipe produced a more blended and comparatively hollow tone while reducing some of the deeper exhaust frequencies.
Separating the banks instead produced:
Greater volume
Deeper exhaust frequencies
Fuller flat-six tone
Increased individual-bank character
A slight additional rasp
More mechanical exhaust texture
SOUL ultimately selected the split-bank architecture for the production Cat Bypass Pipes.
DEEPER, FULLER FLAT-SIX SOUND
The 996 Carrera's naturally aspirated flat-six is especially responsive to changes in the catalyst section.
Removing the original catalysts allows considerably more of the engine's exhaust character to reach the rear mufflers.
Expect:
Louder cold starts
Greater idle presence
Increased acceleration sound
Deeper midrange exhaust tone
Stronger high-RPM presence
Increased throttle-related sound
Additional exhaust rasp
Greater deceleration character
The final sound level depends heavily on the rear mufflers installed behind the Cat Bypass Pipes.
AIR-COOLED-INSPIRED CHARACTER
SOUL describes the split-bank Cat Bypass configuration as having a slight:
air-cooled-inspired exhaust character
due to the combination of:
Deeper frequencies
Independent exhaust banks
Increased mechanical character
Additional rasp
Reduced sound attenuation
This does not mean a 996 becomes acoustically identical to an air-cooled 911, but it describes the direction SOUL pursued when developing the system.
IMPROVED THROTTLE RESPONSE
SOUL specifically identifies improved:
throttle response
and:
overall drivability
as benefits of the Cat Bypass Pipes.
Reducing restriction in the catalyst section allows the naturally aspirated engine to move exhaust gases more freely.
For the driver, SOUL characterizes the result as a more immediate and responsive feel in addition to the increased sound.
PERFORMANCE POTENTIAL
Removing the restrictive factory catalytic converters increases available exhaust-flow capacity.
This can become especially useful when the vehicle also has:
ECU tuning
Intake modifications
Headers
Performance rear mufflers
Other naturally aspirated engine modifications
However, SOUL does not publish a controlled before-and-after dyno result for the Cat Bypass Pipes alone.
DasMotoring therefore does not advertise a specific numerical horsepower or torque gain.
WITH FACTORY SIDE MUFFLERS
The Cat Bypass Pipes can be installed while retaining Porsche's original rear mufflers.
This provides the most conservative catless configuration.
Expect:
Significantly increased engine character
Deeper exhaust tone
Increased throttle response
More high-RPM sound
Retained factory rear muffler attenuation
OEM rear appearance
For a customer wanting substantially more sound without replacing every exhaust component at once, this is the logical starting point.
WITH SOUL SPORT SIDE MUFFLERS
The Cat Bypass Pipes can also be combined with SOUL's Sport Side Mufflers.
The result provides:
Catless catalyst section
Increased flat-six sound
Greater overall volume
Stronger high-RPM character
SOUL's proprietary drone-fighting rear mufflers
Reduced overall exhaust restriction
Because SOUL's Sport Side Mufflers retain significant acoustic control, they can help keep the complete system more manageable than a muffler-delete configuration.
CARRERA 4S COMPATIBILITY
The Cat Bypass Pipes fit the 996 Carrera 4S.
This is important because the standard narrow-body 996 Sport Side Mufflers specifically do not fit the C4S.
The catalyst section is shared, while the rear exhaust architecture differs.
For a Carrera 4S:
SOUL Cat Bypass Pipes: compatible
Standard Carrera Sport Side Mufflers: not compatible
C4S-specific SOUL Side Mufflers: required when upgrading the rear mufflers
TARGA COMPATIBILITY
The same Cat Bypass Pipe assembly also applies to the naturally aspirated 996 Targa.
This makes POR.996.CBP a shared catalyst-delete component across the naturally aspirated Carrera family rather than a body-style-specific exhaust component.
2.25-INCH TUBING
SOUL constructs each bypass assembly from:
2.25-inch outside-diameter tubing
This differs from the 2.5-inch architecture used by SOUL's separate 996 X-Pipe product.
That distinction is important when comparing the two systems.
The Cat Bypass Pipes prioritize SOUL's preferred split-bank sound architecture, while the X-Pipe uses a larger combined-flow design with a different acoustic character.
.065-INCH-WALL T304L STAINLESS STEEL
The pipes are constructed from:
.065-inch-wall T304L stainless steel
This material provides:
High-temperature durability
Corrosion resistance
Structural strength
Low component weight
Long service life
Suitability for repeated street and track heat cycles
MANDREL-BENT TUBING
SOUL uses smooth mandrel bends to preserve the internal tubing geometry through changes in direction.
Maintaining consistent cross-sectional area helps prevent unnecessary restrictions and supports predictable exhaust flow.
THICK EXHAUST FLANGES
The Cat Bypass Pipes use substantial exhaust flanges designed to maintain:
Proper sealing
Correct alignment
Structural rigidity
Durability during repeated thermal cycling
This is especially relevant on vehicles that may now have more than two decades of heat cycling on their original exhaust hardware.
NEW HEADER-FLANGE HARDWARE
SOUL includes new hardware for the connection between the Cat Bypass Pipes and the headers.
This avoids requiring the installer to reuse all of the original aged fasteners at that interface.
Existing downstream exhaust hardware should still be inspected during installation and replaced where necessary.
FIXTURE-TESTED FITMENT
Each set is tested in a dedicated production fixture before shipment.
SOUL verifies:
Flange positioning
Pipe geometry
Downstream exhaust alignment
Overall dimensional consistency
The completed assemblies then undergo quality control and are foam packed for shipping.
6.25-LB WEIGHT REDUCTION
SOUL publishes:
Factory Catalytic Converter Assemblies:
approximately 15 lbs / 6.8 kg
SOUL Cat Bypass Pipes:
approximately 8.75 lbs / 4.0 kg
Weight Savings:
approximately 6.25 lbs / 2.8 kg
That represents approximately a:
42% reduction
in the mass of the factory catalyst assemblies being replaced.
The weight is also removed from the rear of a rear-engined 911.
CAT BYPASS VS. SPORT CATALYTIC CONVERTERS
SOUL Cat Bypass Pipes
$1,555
Completely catless
Split-bank design
2.25-inch T304L construction
Approximately 8.75 lbs
Saves 6.25 lbs
Maximum catalyst-section volume
Greater raw exhaust character
Potential catalyst-related CEL
Competition-oriented configuration
SOUL Sport Catalytic Converters
$3,055
Retain high-flow catalysts
Split-bank design
Approximately 13 lbs
Saves 2 lbs
Developed for catalyst-related CEL-free operation
Reduced exhaust odor
More street-oriented configuration
Both products use SOUL's preferred split-bank architecture.
The primary decision is whether the customer wants to retain catalytic converters.
CAT BYPASS VS. COMPETITION X-PIPE
These are not the same product with different names.
Cat Bypass Pipes
$1,555
Catless
Split-bank
2.25-inch OD tubing
Deeper, fuller tone
8.75 lbs
6.25 lbs saved
Competition X-Pipe
$1,695
Catless
X-pipe
2.5-inch architecture
More blended / hollower sound character
Current X-Pipe page does not publish a verified weight
The $140 price difference is relatively small.
The more important distinction is sound architecture.
CAT BYPASS VS. CATTED X-PIPE
The same basic choice exists for customers who want to retain catalysts:
Sport Catalytic Converters
use SOUL's deeper-sounding split-bank design.
Catted X-Pipe
uses the 2.5-inch X-pipe architecture.
This makes the 996 SOUL catalog unusually flexible because the customer can independently prioritize:
Catalyst retention
Sound character
Exhaust architecture
rather than simply choosing progressively louder versions of the same basic design.
CHECK ENGINE LIGHT
Because the Cat Bypass Pipes completely remove the original catalytic converters, catalyst-monitoring faults may occur.
SOUL explicitly states that this product:
may trigger a check engine light.
DasMotoring therefore does not advertise the Cat Bypass Pipes as CEL-free.
ECU TUNING
The pipes do not require ECU calibration simply to physically bolt onto the vehicle.
However, catalyst removal may result in diagnostic faults.
SOUL recommends contacting them for a tuning solution when catalyst-related faults need to be addressed on an appropriate competition vehicle.
A performance calibration may also be used as part of a broader naturally aspirated engine build.
NO PUBLISHED DYNO NUMBER
SOUL describes improvements in:
Sound
Power
Throttle response
Overall drivability
but does not publish a controlled standalone horsepower or torque figure for POR.996.CBP.
DasMotoring therefore does not advertise a specific numerical power gain.
LIFETIME WARRANTY
SOUL backs the fabricated Cat Bypass Pipes with its:
Lifetime Warranty
for both street and track use.
Unlike a catted system, there is no catalytic-converter substrate with a separate shorter catalyst warranty.
EMISSIONS / COMPETITION USE NOTE
The Cat Bypass Pipes completely remove the original catalytic converters.
SOUL states that this product is:
Not CARB certified
Potentially illegal for use on emissions-controlled vehicles
Intended for off-road / competition use only
Customers are responsible for determining whether their vehicle configuration and intended use comply with applicable regulations.
Product Description
The SOUL X-Pipe is a large-diameter performance catalyst-section upgrade for the 1999–2004 Porsche 996 Carrera, available in either a catless Competition configuration or a catted Sport Catalytic Converter configuration.
Unlike SOUL's standalone 996 Sport Catalytic Converters and Cat Bypass Pipes—which deliberately keep the left and right cylinder banks separated—this system uses an X-pipe architecture to merge the opposing exhaust streams.
SOUL builds the X-Pipe around large 2.5-inch-diameter, .065-inch-wall T304L stainless-steel tubing to reduce exhaust restriction and increase the naturally aspirated flat-six's sound and performance potential.
The Competition version removes the factory catalytic converters entirely for maximum flow and a more aggressive exhaust note. The Catted version incorporates SOUL Sport Catalytic Converters for customers who want the X-pipe architecture while retaining catalysts.
FITMENT:
Fits 1999–2004 Porsche 996 Carrera
Fits 1999–2004 Porsche 996 Carrera Cabriolet
Fits 1999–2004 Porsche 996 Carrera 4
Fits 1999–2004 Porsche 996 Carrera 4 Cabriolet
Fits 2002–2004 Porsche 996 Carrera 4S
Fits applicable 996 Carrera Targa models
Compatible with both 996.1 and 996.2 Carrera
Compatible with the factory rear mufflers
Compatible with SOUL Sport Side Mufflers where applicable
Does not fit 996 Turbo, GT2, or GT3
DETAILS:
Performance X-Pipe catalyst section
Available in Competition / Catless
Available in Catted / Sport Catalytic Converter
Large 2.5-inch diameter tubing
.065-inch wall thickness
T304L stainless-steel construction
X-pipe joins the left and right cylinder-bank exhaust streams
Designed to reduce exhaust restriction
Designed to increase performance potential
Increases naturally aspirated flat-six sound
Smooth mandrel-bent tubing
Thick exhaust flanges
Fixture-tested before shipment
Foam-packed after quality inspection
Direct-fit exhaust architecture
Two catalyst configurations
No exhaust-tip variants
Backed by SOUL Performance Products' Lifetime Warranty for street and track use
LARGE-DIAMETER 2.5-INCH ARCHITECTURE
SOUL builds the 996 Carrera X-Pipe from:
2.5-inch-diameter tubing
The larger flow path is intended to reduce restriction compared with the original Porsche catalyst section and provide additional exhaust capacity for naturally aspirated performance applications.
SOUL specifically developed the system around maximizing flow rather than simply reproducing the dimensions of the factory components.
X-PIPE DESIGN
The defining feature of this product is the connection between the two cylinder banks.
Instead of keeping the left and right exhaust streams completely independent, the X-pipe allows them to merge and interact before continuing toward the rear exhaust.
This changes both:
Exhaust-flow behavior
Exhaust sound character
Compared with SOUL's split-bank catalyst products, the X-pipe produces a different tonal balance and exhaust personality.
IMPORTANT SOUND DIFFERENCE VS. SOUL SPLIT-BANK SYSTEMS
SOUL actually tested split-bank and X-pipe designs back-to-back during development of its 996 exhaust components.
Interestingly, SOUL preferred the split-bank layout for its standalone Sport Catalytic Converters and Cat Bypass Pipes because it preserved more of the deep frequencies of the 996 flat-six.
SOUL found that the X-pipe produced a comparatively:
Smoother sound
More blended exhaust note
Hollower tonal character
Reduced emphasis on some deeper frequencies
That doesn't make one architecture universally better than the other—they simply produce different sound characteristics.
Customers specifically seeking the deepest possible 996 tone may prefer SOUL's split-bank catalyst products, while customers wanting an X-pipe sound and large 2.5-inch flow path should choose this system.
COMPETITION / CATLESS CONFIGURATION
The Competition configuration completely removes the factory catalytic converters.
It combines:
2.5-inch piping
X-pipe architecture
Catless exhaust flow
This is the most aggressive version of the SOUL X-Pipe.
Expect:
Maximum catalyst-section flow
Increased exhaust volume
More raw flat-six character
Greater high-RPM presence
Reduced catalyst restriction
Increased performance potential
Stronger exhaust odor
Potential catalyst-related diagnostic faults
Price: $1,695.00
CATTED CONFIGURATION
The Catted version combines the same X-pipe concept with SOUL's Sport Catalytic Converter configuration.
It retains catalytic converters while offering the larger 2.5-inch X-pipe architecture.
This provides a more conservative alternative for customers who want:
X-pipe exhaust character
Increased exhaust flow
Retained catalysts
Less exhaust odor than the Competition configuration
Reduced diagnostic concerns compared with a completely catless setup
Price: $3,195.00
CATTED VS. COMPETITION
Competition X-Pipe
$1,695
Completely catless
2.5-inch X-pipe
Maximum flow
Maximum catalyst-section sound
Stronger exhaust odor
Potential catalyst-related CEL
Competition-oriented
Catted X-Pipe
$3,195
Retains Sport Catalytic Converters
2.5-inch X-pipe
More conservative sound and emissions behavior
Less exhaust odor
Better suited to customers who want to retain catalysts
Both configurations use the same basic large-diameter X-pipe concept.
X-PIPE VS. SOUL CAT BYPASS PIPES
This is an important distinction within the 996 catalog.
SOUL Cat Bypass Pipes
Catless
Left and right banks remain separated
SOUL specifically selected the split-bank design for a deeper tone
$1,555
SOUL Competition X-Pipe
Catless
Left and right banks are joined through an X-pipe
More blended exhaust character
2.5-inch large-diameter architecture
$1,695
The difference is therefore not simply price.
The two products use different exhaust architectures and produce different sound characteristics.
X-PIPE VS. SOUL SPORT CATALYTIC CONVERTERS
The same distinction applies to the catted versions.
SOUL Sport Catalytic Converters
Catted
Split-bank architecture
Deeper, fuller tone
Approximately 13 lbs
$3,055
SOUL Catted X-Pipe
Catted
X-pipe architecture
More blended sound character
2.5-inch large-diameter tubing
$3,195
The price difference is relatively small, so customer preference should primarily come down to sound architecture rather than cost.
WITH FACTORY SIDE MUFFLERS
The X-Pipe can be used with the original Porsche rear mufflers.
This provides the most conservative overall system.
Expect the X-Pipe to increase:
Flat-six presence
Exhaust flow
Throttle-related sound
High-RPM character
while the factory mufflers continue providing substantial downstream sound attenuation.
WITH SOUL SPORT SIDE MUFFLERS
The X-Pipe can also be combined with SOUL Sport Side Mufflers on compatible Carrera applications.
This creates a substantially more comprehensive exhaust system.
Expect:
Greater overall volume
More mechanical flat-six sound
Increased high-RPM intensity
Reduced exhaust restriction
Greater cabin presence
The SOUL Side Mufflers retain their proprietary drone-control design, which can be particularly useful when the upstream exhaust has also been made freer flowing.
996 CARRERA 4S
The X-Pipe catalyst section is compatible with the 996 Carrera 4S, even though the standard Carrera Sport Side Mufflers are not.
A Carrera 4S therefore needs:
The appropriate shared 996 catalyst/X-pipe component
combined with:
Carrera 4S-specific rear mufflers if upgrading the muffler section
This distinction is important when assembling a complete C4S exhaust package.
T304L STAINLESS CONSTRUCTION
Each system is fabricated from:
.065-inch-wall T304L stainless steel
in:
2.5-inch diameter
T304L provides:
High-temperature durability
Corrosion resistance
Structural strength
Long service life
Consistent exhaust fabrication
Suitability for repeated street and track heat cycles
SMOOTH MANDREL BENDS
SOUL uses mandrel-bent tubing to maintain the intended internal cross-sectional area through bends.
This helps prevent excessive pipe deformation and supports consistent exhaust flow throughout the assembly.
THICK EXHAUST FLANGES
Heavy-duty flanges are used at the exhaust connections to maintain:
Proper sealing
Accurate alignment
Structural stability
Durability through repeated thermal cycling
FIXTURE-TESTED FITMENT
Each SOUL X-Pipe is tested in a dedicated fabrication fixture prior to shipment.
This allows SOUL to verify:
Flange alignment
Pipe geometry
Catalyst positioning where applicable
Downstream exhaust alignment
Overall dimensional consistency
Completed assemblies are then foam packed to protect them during shipment.
PERFORMANCE
SOUL states that the large 2.5-inch architecture is intended to maximize power gains compared with the restrictive factory system.
However, the current product page does not publish a controlled before-and-after dyno result for either X-Pipe configuration.
DasMotoring therefore does not advertise a specific numerical horsepower or torque increase.
WEIGHT
SOUL's current X-Pipe page does not publish a verified weight for either the Competition or Catted X-Pipe configuration.
Although weight data exists for the standalone Cat Bypass Pipes and Sport Catalytic Converters, those use a different split-bank architecture.
DasMotoring therefore does not apply those weights to the X-Pipe product.
CHECK ENGINE LIGHT — COMPETITION VERSION
The Competition configuration removes the catalytic converters.
Because catalyst functionality is eliminated, catalyst-related diagnostic faults may occur.
An appropriate competition ECU calibration may be necessary for diagnostic management depending on the vehicle.
CATTED CONFIGURATION AND CEL BEHAVIOR
The Catted X-Pipe retains SOUL Sport Catalytic Converters.
SOUL's standalone Sport Catalytic Converters are developed around CEL-free operation, but the current dedicated X-Pipe page does not separately publish a diagnostic guarantee for the XP.SCC configuration.
DasMotoring therefore avoids making an absolute CEL guarantee for the catted X-Pipe.
ECU TUNING
No ECU calibration is required simply for the X-Pipe hardware to physically fit the vehicle.
For the catless Competition configuration, tuning may be appropriate to manage catalyst-related diagnostic faults and optimize a modified engine.
For the Catted configuration, tuning is not specified as a requirement.
EMISSIONS / COMPETITION USE NOTE
The Competition X-Pipe removes the factory catalytic converters and is intended for off-road / closed-course competition applications.
SOUL states that the product is not CARB certified and may not be legal for use on emissions-controlled vehicles.
The Catted configuration retains aftermarket Sport Catalytic Converters but should not be represented as original Porsche emissions equipment.
Customers are responsible for determining compliance with applicable regulations.
Product Description
The SOUL Competition Headers are a direct bolt-on performance upgrade for the 1999–2004 Porsche 996 Carrera, replacing the restrictive factory exhaust manifolds with equal-length T304L stainless-steel runners and true 3-into-1 merge collectors.
Unlike many products carrying the “Competition” name, these headers do not remove the catalytic converters. On the 996 Carrera, Porsche locates the catalysts farther downstream in the rear exhaust assemblies, allowing SOUL to focus entirely on improving exhaust flow between the cylinder heads and the existing catalyst section.
SOUL improves the factory flow path with port-matched flanges, smooth-radius large-diameter primary tubes, equal-length runners, and a collector that gives each cylinder a more effective path into a true 3-to-1 merge. The factory manifolds do not use the same true merge-collector architecture.
The result is improved exhaust flow, stronger throttle response, and noticeably greater torque under acceleration without requiring removal of the vehicle's catalytic converters or changing the basic emissions architecture.
SOUL also designed the headers with increased internal volume to better support the later 3.6L 996 Carrera engines, while retaining compatibility across the complete naturally aspirated 996 Carrera range.
FITMENT:
Fits 1999–2004 Porsche 996 911 Carrera
Fits 1999–2004 Porsche 996 911 Carrera Cabriolet
Fits 1999–2004 Porsche 996 911 Carrera 4
Fits 1999–2004 Porsche 996 911 Carrera 4 Cabriolet
Fits 2002–2004 Porsche 996 911 Carrera 4S
Fits 2004 Porsche 996 911 Carrera 4S Cabriolet
Fits applicable 2002–2004 Porsche 996 911 Targa
Compatible with 996.1 and 996.2 Carrera
Compatible with naturally aspirated 3.4L and 3.6L Carrera engines
Compatible with the factory catalytic-converter assemblies
Compatible with SOUL Sport Catalytic Converters
Compatible with SOUL Cat Bypass Pipes
Compatible with SOUL 996 X-Pipe configurations
Compatible with factory or appropriate SOUL rear mufflers
Does not fit 996 Turbo, GT2, or GT3 applications
DETAILS:
Pair of performance Competition Headers
Equal-length primary runners
True 3-into-1 merge collectors
Improves on the factory manifold's non-merge collector architecture
Port-matched cylinder-head flanges
Smooth flange-to-primary transitions
Smooth-radius primary tubing
Large-diameter primary bends
Equalized collector inputs from all three cylinders
Increased internal volume for later 3.6L applications
Designed to improve exhaust flow
Designed to increase usable torque and response
Retains downstream catalytic converters when used with the factory exhaust
Does not require catalyst removal
Does not inherently alter oxygen-sensor or catalyst-monitoring architecture
T304L stainless-steel construction
Direct bolt-on installation
Approximately 2 lbs / 0.9 kg lighter than the corresponding factory header components
Fixture-tested before shipment
Foam-packed after quality control
Detailed installation instructions included
No product variants
Backed by SOUL Performance Products' Lifetime Warranty for street and track use
TRUE 3-INTO-1 MERGE COLLECTORS
One of the most significant differences between the factory manifolds and the SOUL Competition Headers is the collector design.
Each bank of Porsche's flat-six must combine three individual exhaust runners into a single outlet.
The original manifolds do not use what SOUL considers a true:
3-into-1 merge collector
SOUL redesigns this area so that each primary runner feeds the collector more evenly.
The goal is to create a smoother transition from:
Cylinder Head → Primary Runner → Merge Collector → Downstream Exhaust
rather than forcing the gases through the less optimized factory junction.
EQUAL-LENGTH PRIMARY RUNNERS
SOUL uses equal-length runners to provide a more consistent path from each cylinder to the collector.
This architecture is intended to improve how the exhaust pulses from all three cylinders on each bank enter the collector.
The design focuses on:
Consistent exhaust routing
Improved collector entry
Smoother exhaust flow
Better utilization of exhaust pulse energy
Increased performance potential
PORT-MATCHED FLANGES
The transition immediately after the cylinder head is an important part of header design.
SOUL uses port-matched flanges to create a cleaner interface between the cylinder-head exhaust ports and the primary tubes.
An abrupt step or poorly matched transition can create unnecessary turbulence at the beginning of the exhaust path.
SOUL instead focuses on smoothing the transition from the flange into the primary runners.
SMOOTH FLANGE-TO-PRIMARY TRANSITION
The SOUL design specifically addresses the interface between:
Flange → Primary Tube
This area is optimized to reduce abrupt changes in geometry as the exhaust gases leave the cylinder head.
The objective is a cleaner path through the entire manifold rather than simply using larger tubing.
SMOOTH-RADIUS PRIMARY TUBING
SOUL uses smooth-radius bends through the primary runners rather than abrupt exhaust routing.
This helps maintain:
Consistent internal geometry
Exhaust velocity
Smooth directional changes
Reduced localized restriction
The result is a more carefully controlled exhaust path before the gases reach the collector.
DESIGNED FOR BOTH 3.4L AND 3.6L ENGINES
The 996 Carrera platform spans both:
3.4L
and
3.6L
naturally aspirated flat-six engines.
SOUL specifically notes that its header design provides greater internal volume for the 3.6L applications while remaining compatible across the 1999–2004 Carrera platform.
This allows one header design to serve the complete naturally aspirated 996 Carrera family.
IMPROVED EXHAUST FLOW
The factory 996 Carrera manifolds leave room for improvement in several areas:
Primary-runner transition
Bend geometry
Collector design
Collector entry from each cylinder
SOUL addresses all of these areas simultaneously.
Rather than focusing on one oversized pipe dimension, the system improves the complete path from the cylinder head into the downstream exhaust.
STRONGER TORQUE RESPONSE
SOUL specifically describes the Competition Headers as producing noticeably more torque when the throttle is applied.
This makes sense as a header-focused modification because the goal is not simply maximum peak horsepower at redline.
Improving exhaust flow can also affect:
Midrange response
Part-throttle response
Engine willingness to rev
Acceleration throughout the usable RPM range
SOUL does not publish a numerical torque gain, so DasMotoring does not assign a specific lb-ft figure to the headers.
NO PUBLISHED DYNO NUMBER
The current SOUL product page does not provide a controlled factory-header versus Competition-Header dyno chart.
SOUL describes increased exhaust flow, stronger torque, and increased power potential, but does not publish a verified:
Peak horsepower gain
Peak torque gain
RPM-specific gain
DasMotoring therefore does not advertise a numerical horsepower or torque increase for this product.
RETAINS THE CATALYTIC CONVERTERS
The term Competition Headers can easily create the impression that this is a catless product.
It is not.
On the 996 Carrera, the catalytic converters are incorporated farther downstream in the rear exhaust system.
The headers themselves replace only the original exhaust manifolds.
When installed with the original rear exhaust, the vehicle retains:
Factory catalytic converters
Factory catalyst monitoring
Downstream emissions hardware
Factory mufflers
This makes the headers fundamentally different from SOUL's:
Cat Bypass Pipes
Competition X-Pipe
both of which can remove the catalytic converters.
NO CATALYST-RELATED CEL EXPECTED FROM THE HEADERS
Because the Competition Headers do not remove the catalytic converters or alter the catalyst-monitoring architecture, SOUL specifically developed the system without introducing check-engine-light issues associated with catalyst deletion.
This does not mean that no 20+ year-old vehicle can ever produce a diagnostic fault, but there is no catalyst-delete mechanism inherent to the header installation itself.
NO ECU TUNE REQUIRED
SOUL does not specify ECU calibration as a requirement for installation.
The headers are designed as a mechanical bolt-on upgrade.
A tune may potentially extract additional benefit when combined with other engine modifications, but it is not necessary simply to install the headers.
WITH FACTORY CATALYTIC CONVERTERS
The simplest configuration is:
SOUL Competition Headers + Factory Catalysts + Factory Rear Exhaust
This provides:
Improved header flow
True 3-into-1 merge collectors
Reduced header weight
Retained factory catalysts
Retained factory mufflers
Comparatively subtle sound change
For a customer primarily interested in improving engine response without dramatically increasing exhaust volume, this is a logical first-stage configuration.
WITH SOUL SPORT CATALYTIC CONVERTERS
Pairing the Competition Headers with the SOUL Sport Catalytic Converters creates a more comprehensive performance exhaust configuration.
The combination addresses:
Headers:
Flow immediately after the cylinder heads
and
Sport Catalytic Converters:
Restriction farther downstream in the catalyst section
This provides:
Improved manifold flow
High-flow catalysts
Increased flat-six sound
Reduced exhaust restriction
Greater overall performance potential
while retaining catalytic converters.
WITH SOUL CAT BYPASS PIPES
For a more aggressive configuration, the headers can be paired with SOUL Cat Bypass Pipes.
This combines:
Equal-length headers
True 3-to-1 merge collectors
Catless split-bank catalyst replacement
Reduced exhaust restriction
Greater flat-six volume
Increased exhaust character
The emissions and CEL considerations in this configuration are created by the Cat Bypass Pipes, not by the Competition Headers themselves.
WITH SOUL X-PIPE
The Competition Headers are also compatible with SOUL's larger 996 X-Pipe architecture.
Depending on the selected X-Pipe configuration, the customer can choose:
Catted X-Pipe
Catless Competition X-Pipe
This gives the owner considerable flexibility in building the rest of the exhaust downstream from the headers.
WITH FACTORY REAR MUFFLERS
Because the headers do not require a rear exhaust replacement, they can be installed while retaining the factory mufflers.
This configuration maintains the greatest amount of Porsche's original sound attenuation.
Any sound increase from the headers themselves should therefore remain significantly more restrained than changes produced by replacing the catalyst or rear muffler sections.
WITH SOUL SPORT SIDE MUFFLERS
Combining the Competition Headers with SOUL Sport Side Mufflers further increases naturally aspirated flat-six character while retaining SOUL's proprietary drone-control strategy.
A full street-oriented SOUL configuration can therefore combine:
Competition Headers
Sport Catalytic Converters
Sport Side Mufflers
for improvements throughout the exhaust system without requiring a completely catless configuration.
2-LB WEIGHT REDUCTION
SOUL specifies that the Competition Headers weigh approximately:
2 lbs / 0.9 kg less
than the corresponding factory components.
SOUL does not currently publish the individual absolute weights of:
Factory headers
SOUL Competition Headers
so DasMotoring does not invent or extrapolate those figures.
T304L STAINLESS-STEEL CONSTRUCTION
The Competition Headers are fabricated from:
T304L stainless steel
This material provides:
High-temperature durability
Corrosion resistance
Structural strength
Long service life
Suitability for repeated street and track heat cycling
SOUL does not currently publish a wall thickness for this product, so DasMotoring does not assign one.
FIXTURE-TESTED FITMENT
Each set of Competition Headers is tested in a dedicated manufacturing fixture before shipment.
This helps verify:
Cylinder-head flange alignment
Primary-runner positioning
Collector alignment
Downstream exhaust fitment
Overall dimensional consistency
Each set is then quality inspected and foam packed before shipment.
DIRECT BOLT-ON INSTALLATION
SOUL describes these headers as one of the easier performance upgrades available for the 996 Carrera.
The system is designed as a direct bolt-on replacement for the original manifolds.
SOUL includes detailed installation instructions, and no permanent chassis modification is required for normal installation.
COMPETITION HEADERS VS. FACTORY HEADERS
Factory Headers
Non-optimized collector architecture
No true 3-into-1 merge collector
Less optimized flange-to-primary transition
Factory exhaust flow characteristics
Approximately 2 lbs heavier
SOUL Competition Headers
Equal-length runners
True 3-into-1 merge collectors
Port-matched flanges
Smooth-radius primary tubing
More equal collector inputs
Increased internal volume for 3.6L applications
Approximately 2 lbs lighter
Retains downstream catalyst compatibility
COMPETITION DOES NOT MEAN CATLESS
Within the SOUL 996 catalog, the naming can be confusing.
Competition Headers
do not remove the catalytic converters.
By contrast:
Competition X-Pipe
is the catless X-pipe configuration.
The Competition Header name refers to the performance-oriented manifold design, not catalyst deletion.
This distinction is important when building a complete DasMotoring exhaust package.
Product Description
The SOUL Valved Side Mufflers are a premium dual-mode exhaust upgrade developed specifically for the 2002–2004 Porsche 996 Carrera 4S equipped with Porsche Sport Exhaust / PSE, preserving the factory exhaust-valve controls while dramatically expanding the range between quiet cruising and aggressive performance sound.
With the valves open, SOUL's freer-flowing exhaust path delivers a Cup car-inspired naturally aspirated flat-six sound with substantially greater volume, mechanical character, and high-RPM intensity. Close the valves and exhaust is redirected through SOUL's proprietary drone-fighting mufflers, significantly reducing cabin resonance and creating a refined sound appropriate for commuting, highway driving, and longer trips.
Because the system is fully compatible with the Carrera 4S's factory valve controls, there is no need to replace Porsche's original PSE operating strategy with a separate aftermarket controller.
The SOUL Valved Side Mufflers weigh approximately 35.4 lbs compared with 49.9 lbs for the factory PSE exhaust system, removing approximately 14.5 lbs / 6.5 kg from the rear of the car.
FITMENT:
Fits 2002–2004 Porsche 996 911 Carrera 4S Coupe with factory PSE
Fits 2004 Porsche 996 911 Carrera 4S Cabriolet with factory PSE
Designed specifically for the 996 Carrera 4S
Designed for the naturally aspirated 3.6L flat-six
Factory Porsche Sport Exhaust / PSE valve controls retained
Compatible with the factory catalytic converters
Compatible with SOUL Sport Catalytic Converters
Compatible with SOUL Cat Bypass Pipes
Compatible with applicable SOUL 996 catalyst and X-pipe components
Does not fit standard narrow-body 996 Carrera / Carrera 4 / Targa rear-muffler applications
Does not fit 996 Turbo, GT2, or GT3
DETAILS:
Pair of Valved Side Mufflers
True dual-mode exhaust operation
Fully compatible with factory Porsche exhaust-valve controls
Aggressive, freer-flowing exhaust character with valves open
Cup car-inspired valves-open sound
Proprietary SOUL drone-fighting mufflers with valves closed
Refined cabin presence during cruising
Designed to minimize undesirable cabin resonance
Particularly effective even when paired with aftermarket catalyst upgrades
Increased naturally aspirated flat-six volume and mechanical tone
Transformational difference between open and closed modes
Approximately 35.4 lbs / 16.1 kg
Factory PSE exhaust system approximately 49.9 lbs / 22.6 kg
Saves approximately 14.5 lbs / 6.5 kg
Approximately 29% lighter than the corresponding factory PSE exhaust
Mandrel-bent T304L stainless-steel construction
.060-inch wall thickness
Bespoke SOUL mufflers
Laser-cut mounting brackets
Nearly 15 fabrication man-hours per set
Built and tested in thick-gauge aluminum fixtures
Fixture-tested prior to shipment
Quality checked and foam packed
Available with Polished Chrome tips
Available with Black Chrome tips
Designed and built in Willow Grove, Pennsylvania
Backed by SOUL Performance Products' Lifetime Warranty for street and track use
DESIGNED FOR FACTORY PSE CARRERA 4S
The 996 Carrera 4S was available with Porsche Sport Exhaust, giving the car two distinct exhaust behaviors through factory-controlled exhaust valves.
SOUL designed this system specifically to preserve that functionality while significantly improving both modes.
Rather than converting the car to a permanently loud exhaust, the Valved Side Mufflers retain the ability to switch between:
Refined / Valves Closed
and
Aggressive / Valves Open
using the Porsche factory valve-control system.
FULL FACTORY VALVE-CONTROL COMPATIBILITY
SOUL specifically states that the Valved Side Mufflers are:
Fully compatible with the factory valve controls.
That means the vehicle's existing PSE functionality remains integral to the system.
There is no need to add a separate aftermarket valve controller simply to operate the SOUL mufflers on an appropriately equipped Carrera 4S.
This is one of the primary differences between these mufflers and universal aftermarket valved systems.
VALVES OPEN
With the valves open, SOUL prioritizes a freer-flowing and much more aggressive exhaust character.
SOUL describes the result as:
Cup car-inspired sound.
Expect substantially greater:
Flat-six engine character
Acceleration volume
Mechanical exhaust tone
High-RPM intensity
Throttle-related feedback
Gear-change sound
Deceleration presence
The naturally aspirated 3.6L flat-six becomes significantly more prominent than with the original PSE mufflers.
CUP CAR-INSPIRED CHARACTER
The valves-open mode is intended to give the Carrera 4S a much more motorsport-oriented character.
Rather than simply making the exhaust deeper, SOUL emphasizes the mechanical and higher-energy frequencies of the flat-six when the aggressive path is active.
The effect becomes particularly noticeable as engine speed increases.
This gives the car a much more dramatic personality during:
Back-road driving
High-RPM acceleration
Track use
Downshifts
Full-throttle operation
VALVES CLOSED
Closing the valves places SOUL's proprietary drone-fighting mufflers back at the center of the exhaust path.
The objective is to create a dramatically calmer driving experience without eliminating the increased character of the upgraded system entirely.
With the valves closed, expect:
Lower exterior volume
Reduced cabin presence
Reduced low-frequency resonance
More comfortable highway cruising
More restrained neighborhood operation
Greater long-distance usability
PROPRIETARY DRONE-FIGHTING MUFFLERS
SOUL developed the quieter path around bespoke mufflers specifically intended to control undesirable cabin resonance.
This is particularly valuable on the 996 platform because aggressive catalyst and muffler modifications can easily introduce:
Low-frequency drone
Booming cabin resonance
Harshness
Excessive cruising volume
SOUL's goal was to retain a genuinely useful quiet mode rather than simply making one valve position slightly less loud.
TWO DISTINCT PERSONALITIES
The defining characteristic of this system is the difference between its two operating modes.
Valves Closed
Refined
Drone controlled
Street friendly
Comfortable for commuting
Suitable for longer drives
Valves Open
Aggressive
Freer flowing
Cup car inspired
Much greater flat-six presence
Dramatically increased high-RPM sound
SOUL describes the result as an OEM-plus system with transformational potential.
DESIGNED FOR DAILY USE
A 996 Carrera 4S is old enough today that many examples are enthusiast cars, but that does not necessarily mean owners want a permanently loud exhaust.
SOUL's dual-mode architecture allows the exhaust to remain suitable for:
Daily driving
Commuting
Highway trips
Residential areas
while still providing a much more aggressive experience when desired.
DEVELOPED TO WORK WITH AFTERMARKET CATALYSTS
SOUL specifically notes that the valves-open sound can be further amplified with aftermarket catalyst replacements.
More importantly, the valves-closed drone-fighting mufflers remain useful even when additional upstream exhaust modifications are installed.
This makes the system particularly well suited to a Carrera 4S that may eventually receive:
SOUL Sport Catalytic Converters
SOUL Cat Bypass Pipes
SOUL X-Pipe components
SOUL Competition Headers
WITH FACTORY CATALYTIC CONVERTERS
With Porsche's original catalytic converters retained, the Valved Side Mufflers provide the most conservative overall setup.
Expect:
Valves Closed
Refined sound
Controlled cruising volume
Factory catalysts providing additional acoustic attenuation
Valves Open
Strong increase in flat-six character
More high-RPM sound
Greater mechanical tone
More aggressive throttle response acoustically
This is a strong configuration for a customer primarily interested in improving sound while leaving the upstream exhaust system original.
WITH SOUL SPORT CATALYTIC CONVERTERS
Pairing the Valved Side Mufflers with SOUL Sport Catalytic Converters provides a more comprehensive street-oriented exhaust system.
The Sport Cats add:
Increased exhaust flow
Deeper flat-six sound
Greater overall volume
Reduced catalyst restriction
while the Valved Side Mufflers retain the ability to significantly reduce cabin presence when desired.
This combination offers a much wider range of sound than using fixed Sport Side Mufflers with the same high-flow catalysts.
WITH SOUL CAT BYPASS PIPES
Pairing the Valved Side Mufflers with SOUL Cat Bypass Pipes creates a considerably more aggressive configuration.
Expect substantially more:
Exhaust volume
Raw flat-six sound
High-RPM intensity
Deceleration character
Cabin presence
with the valves open.
The presence of SOUL's drone-fighting muffler path becomes particularly valuable in this configuration because closing the valves provides meaningful acoustic control over an otherwise highly aggressive catless exhaust.
WITH SOUL COMPETITION HEADERS
The Valved Side Mufflers can also be combined with the shared SOUL 996 Carrera Competition Headers.
Those headers improve exhaust flow immediately after the cylinder heads through:
Equal-length runners
True 3-into-1 merge collectors
Improved flange-to-primary transitions
while the Valved Side Mufflers manage the sound farther downstream.
DEDICATED CARRERA 4S REAR EXHAUST
The Carrera 4S uses different rear packaging from the normal narrow-body Carrera.
SOUL therefore developed a dedicated C4S exhaust rather than adapting the standard Carrera mufflers.
This product should not be confused with the standard:
996 Carrera Sport Side Mufflers
which explicitly do not fit the C4S.
VALVED VS. SPORT SIDE MUFFLERS
SOUL offers two dedicated rear-muffler solutions for the Carrera 4S.
SOUL Sport Side Mufflers
Start at $3,175
Fixed / non-valved sound
Proprietary drone-fighting mufflers
Increased flat-six sound
Refined OEM-plus character
Simpler architecture
Lower price
SOUL Valved Side Mufflers
Start at $4,555
Retain factory PSE valve control
Two distinct sound modes
Cup car-inspired valves-open character
Drone-fighting valves-closed operation
Approximately 14.5 lbs lighter than factory PSE
Much wider range of sound
For a factory-PSE-equipped C4S, the Valved Side Mufflers are the more complete solution if preserving active exhaust control matters.
14.5-LB WEIGHT REDUCTION
SOUL publishes:
Factory PSE Exhaust System:
approximately 49.9 lbs / 22.6 kg
SOUL Valved Side Mufflers:
approximately 35.4 lbs / 16.1 kg
Weight Savings:
approximately 14.5 lbs / 6.5 kg
That represents approximately a:
29% reduction
in the mass of the exhaust components being replaced.
This is a much larger weight reduction than the standard Carrera Sport Side Muffler system.
REAR-MOUNTED WEIGHT SAVINGS
The 14.5-lb reduction is particularly useful on a rear-engined 911 because the factory mufflers are positioned toward the back of the car.
While 14.5 lbs alone will not fundamentally change vehicle balance, reducing unnecessary mass at the extreme rear is directionally beneficial for a performance-oriented build.
.060-INCH-WALL T304L STAINLESS STEEL
SOUL constructs the system from:
Mandrel-bent .060-inch-wall T304L stainless-steel tubing
The comparatively thin-wall construction helps balance:
Durability
Strength
Corrosion resistance
Reduced mass
High-temperature performance
SOUL's current page does not publish an exact tubing diameter, so DasMotoring does not assign one.
BESPOKE SOUL MUFFLERS
The system uses mufflers developed specifically for the intended sound and resonance behavior of this application.
These are not simply generic universal mufflers welded into model-specific pipework.
The muffler architecture is central to producing the quieter valves-closed experience.
LASER-CUT BRACKETS
SOUL uses precision laser-cut brackets to locate the exhaust correctly within the Carrera 4S rear chassis.
Accurate mounting geometry helps maintain:
Muffler position
Exhaust-tip alignment
Chassis clearance
Valve-system alignment
Consistent installation
NEARLY 15 MAN-HOURS PER SET
SOUL states that nearly:
15 man-hours
of fabrication labor are invested into each set of Valved Side Mufflers.
The labor-intensive construction reflects the added complexity of producing:
Two exhaust flow behaviors
Valved routing
Bespoke mufflers
Model-specific brackets
Accurate tip alignment
within the restricted packaging available behind the 996 Carrera 4S.
THICK-GAUGE ALUMINUM FIXTURES
Each exhaust is built and tested in a thick-gauge aluminum fabrication fixture.
The fixture helps control heat-related distortion and maintains repeatable:
Pipe geometry
Muffler position
Valve positioning
Mounting-point alignment
Exhaust-tip alignment
FIXTURE-TESTED FITMENT
Every system is checked in its production fixture before shipment.
SOUL performs a final quality-control inspection and then foam packs the mufflers to help protect the finished components in transit.
POLISHED CHROME TIPS
The Polished Chrome configuration provides a traditional bright-metal appearance appropriate to the period styling of the 996 Carrera 4S.
Price: $4,555.00
BLACK CHROME TIPS
The Black Chrome configuration provides a darker and more understated rear appearance.
Price: $4,795.00
The Black Chrome option carries a:
$240 premium
over Polished Chrome.
NO PUBLISHED HORSEPOWER CLAIM
SOUL does not publish a controlled stock-PSE-versus-Valved-Side-Muffler dyno comparison for this product.
The system's primary documented benefits are:
Sound control
Increased valves-open sound
Reduced valves-closed resonance
Factory PSE integration
Substantial weight reduction
DasMotoring therefore does not advertise a numerical horsepower or torque increase from the mufflers alone.
NO ECU TUNE REQUIRED
No ECU calibration is required to install the Valved Side Mufflers.
On a properly equipped Carrera 4S, the system uses the existing factory valve-control functionality.
The mufflers do not themselves replace:
Catalytic converters
Oxygen sensors
Headers
ECU hardware
EMISSIONS SYSTEM REMAINS UPSTREAM
The Valved Side Mufflers are downstream exhaust components.
Installing the mufflers alone does not remove the vehicle's catalytic converters.
Emissions considerations will depend on whatever upstream catalyst configuration is installed on the vehicle.
Product Description
The SOUL Sport Side Mufflers are a dedicated exhaust upgrade for the 2002–2004 Porsche 996 Carrera 4S, developed specifically around the C4S's unique wide-body rear exhaust packaging.
SOUL uses proprietary drone-fighting mufflers to increase the naturally aspirated 3.6L flat-six's volume and mechanical character under moderate and aggressive throttle while maintaining a refined, OEM-plus cabin presence during cruising.
Rather than simply making the 996 louder, SOUL focused on avoiding the excessive rasp, harshness, and low-frequency cabin resonance that can result from overly aggressive exhaust modifications. The Sport Side Mufflers were developed alongside SOUL's high-flow catalytic-converter upgrades so that the system remains controlled even when additional upstream exhaust restriction is removed.
Each system is hand fabricated from 2.25-inch, .065-inch-wall T304L stainless-steel tubing, bespoke SOUL mufflers, and laser-cut brackets. Polished Chrome and Black Chrome exhaust-tip finishes are available.
FITMENT:
Fits 2002–2004 Porsche 996 911 Carrera 4S Coupe
Fits 2004 Porsche 996 911 Carrera 4S Cabriolet
Designed specifically for the 996 Carrera 4S
Designed for the naturally aspirated 3.6L flat-six
Dedicated C4S rear-muffler architecture
Compatible with factory catalytic converters
Compatible with SOUL Sport Catalytic Converters
Compatible with SOUL Cat Bypass Pipes
Compatible with applicable SOUL 996 catalyst / X-pipe components
Does not fit standard narrow-body 996 Carrera / Carrera 4 / Targa muffler applications
Does not fit 996 Turbo, GT2, or GT3
DETAILS:
Pair of dedicated Carrera 4S Sport Side Mufflers
Proprietary SOUL drone-fighting muffler design
Designed for increased naturally aspirated flat-six sound
Increased mechanical engine tone under throttle
Refined OEM-plus cruising character
Designed to minimize undesirable cabin resonance
Developed to avoid excessive rasp
Designed to remain refined with upgraded high-flow catalytic converters
Fixed, non-valved exhaust architecture
2.25-inch diameter tubing
.065-inch wall thickness
T304L stainless-steel construction
Smooth mandrel-bent tubing
Bespoke SOUL mufflers
Laser-cut mounting brackets
Back-purged TIG welding
ARCAL Prime argon shielding gas used during fabrication
Built in thick-gauge aluminum fixtures to control distortion
Fixture-tested prior to shipment
New high-grade bolts, washers, and nuts included
Available with Polished Chrome tips
Available with Black Chrome tips
Designed and manufactured in Willow Grove, Pennsylvania
Backed by SOUL Performance Products' Lifetime Warranty for street and track use
DEDICATED CARRERA 4S DESIGN
The 996 Carrera 4S uses different rear exhaust packaging from the standard narrow-body Carrera.
For that reason, SOUL offers these as a dedicated C4S muffler system rather than using the standard 996 Carrera Sport Side Mufflers.
This distinction is important:
Standard 996 Carrera Sport Side Mufflers
do not fit the Carrera 4S.
The C4S requires this dedicated system.
PROPRIETARY DRONE-FIGHTING MUFFLERS
The core of the system is SOUL's proprietary muffler design.
SOUL's goal was to increase the desirable mechanical frequencies of the flat-six without introducing the unpleasant characteristics often associated with aggressively modified 996 exhaust systems.
The mufflers are designed to provide:
Increased sound under acceleration
Greater flat-six mechanical character
Stronger high-RPM presence
Controlled low-RPM resonance
Refined highway cruising
Reduced undesirable drone
This makes the system particularly appropriate for a street-driven Carrera 4S.
OEM-PLUS CRUISING CHARACTER
During steady-speed cruising, the system is intended to maintain a relatively restrained cabin environment.
SOUL specifically focuses on preserving an:
OEM-plus cabin presence
rather than producing constant high exhaust volume.
The mufflers contain substantial sound-attenuating material to control unwanted frequencies during normal driving.
MORE SOUND UNDER THROTTLE
The character changes as engine load increases.
Under moderate and aggressive throttle, expect:
Increased exhaust volume
More mechanical flat-six tone
Stronger acceleration sound
Greater high-RPM presence
More direct throttle-related feedback
The system therefore becomes substantially more engaging when the car is driven hard without requiring constant high volume during normal cruising.
DEVELOPED TO AVOID RASP
The naturally aspirated 996 responds strongly to catalyst and muffler changes.
Unfortunately, removing too much sound attenuation can also create a metallic or excessively raspy exhaust tone.
SOUL specifically developed the Sport Side Mufflers to avoid that result.
The objective was a system with:
Greater volume
Greater engine character
More aggressive sound
without:
Excessive rasp
Harsh resonance
Booming cabin frequencies
Fatiguing highway noise
DEVELOPED WITH SPORT CATALYTIC CONVERTERS
SOUL developed these mufflers while using freer-flowing Sport Catalytic Converters.
That is important because reducing catalyst restriction increases both exhaust energy and sound before the gases reach the rear mufflers.
The Sport Side Mufflers therefore include enough acoustic control to remain usable even when paired with upgraded catalysts.
WITH FACTORY CATALYTIC CONVERTERS
With the original Porsche catalysts retained, the Sport Side Mufflers provide the most conservative configuration.
Expect:
Increased flat-six tone
Greater acceleration volume
More mechanical character
Retained factory catalyst attenuation
Comfortable cruising behavior
This is a good configuration for an owner wanting improved sound without dramatically changing the rest of the exhaust.
WITH SOUL SPORT CATALYTIC CONVERTERS
Pairing the mufflers with SOUL Sport Catalytic Converters creates a more complete street-oriented exhaust system.
The combination provides:
Increased exhaust flow
Greater naturally aspirated flat-six character
Increased overall volume
Deeper and more mechanical exhaust tone
High-flow catalysts
SOUL's proprietary drone control
This is one of the more balanced complete exhaust combinations for a street-driven 996 Carrera 4S.
WITH SOUL CAT BYPASS PIPES
For a substantially more aggressive configuration, the Sport Side Mufflers can be paired with SOUL Cat Bypass Pipes.
Expect:
Much greater exhaust volume
More raw exhaust character
Additional high-frequency content
Increased deceleration sound
Greater cabin presence
The Sport Side Mufflers will continue providing more acoustic control than a muffler-delete system, but removing the catalysts significantly changes the overall sound level and character.
FIXED / NON-VALVED DESIGN
These Sport Side Mufflers are a fixed, non-valved exhaust system.
There is no active quiet mode or exhaust-valve control built into this product.
SOUL separately offers 996 Carrera 4S Valved Side Mufflers for customers who want to retain a factory-style dual-mode exhaust experience.
For a Carrera 4S originally equipped with Porsche Sport Exhaust, the Valved Side Mufflers are the more appropriate SOUL product if retaining valve functionality is important.
SPORT SIDE MUFFLERS VS. VALVED SIDE MUFFLERS
SOUL Sport Side Mufflers
Start at $3,175
Fixed exhaust character
Proprietary drone-fighting mufflers
Increased flat-six sound under throttle
Refined cruising behavior
Simpler architecture
Lower purchase price
SOUL Valved Side Mufflers
Start at $4,555
Active exhaust valves
Quiet valves-closed mode
Free-flowing valves-open mode
Cup-car-inspired open-valve sound
Compatible with factory valve controls
Greater range between quiet and aggressive operation
Customers who do not need active sound control can save substantial cost with the Sport Side Mufflers.
2.25-INCH TUBING
SOUL constructs the system from:
2.25-inch-diameter tubing
This size is appropriately matched to the naturally aspirated 3.6L Carrera 4S application.
The design prioritizes:
Exhaust velocity
Packaging
Sound quality
Consistent fitment
Street drivability
rather than unnecessarily oversized tubing.
.065-INCH-WALL T304L STAINLESS STEEL
Each muffler assembly is constructed from:
.065-inch-wall T304L stainless steel
T304L provides:
High-temperature durability
Corrosion resistance
Structural strength
Long service life
Suitable durability for street and track heat cycles
MANDREL-BENT TUBING
SOUL uses mandrel-bent tubing to preserve internal cross-sectional area through each bend.
This helps maintain consistent:
Tubing diameter
Exhaust flow
Internal geometry
Fitment
through the compact rear packaging of the Carrera 4S.
LASER-CUT BRACKETS
Precision laser-cut brackets locate the mufflers within the C4S rear chassis.
Consistent bracket geometry helps maintain:
Correct muffler position
Exhaust-tip alignment
Chassis clearance
Mounting-point alignment
BACK-PURGED TIG WELDING
SOUL uses back-purged TIG welding during fabrication.
SOUL specifically uses:
ARCAL Prime argon
as its shielding gas.
Back purging helps provide:
Cleaner internal weld surfaces
Proper weld penetration
Reduced internal oxidation
Long-term durability
THICK-GAUGE ALUMINUM FIXTURES
Each set is built and tested in a thick-gauge aluminum fixture.
The fixture helps control distortion from the heat generated during welding.
This supports consistent:
Muffler location
Tubing geometry
Bracket positioning
Tip alignment
from one system to the next.
FIXTURE-TESTED FITMENT
Every completed exhaust is checked in its production fixture before shipment.
SOUL then performs final quality control and foam packs the mufflers to help protect them during transportation.
NEW INSTALLATION HARDWARE
SOUL supplies new:
High-grade bolts
Washers
Nuts
with the system.
This reduces the need to reuse all of the original 20-plus-year-old muffler hardware during installation.
Existing clamps, fasteners, and surrounding exhaust hardware should still be inspected and replaced where necessary.
POLISHED CHROME TIPS
The Polished Chrome configuration provides a bright, traditional exhaust finish that complements the period styling of the 996 Carrera 4S.
Price: $3,175.00
BLACK CHROME TIPS
The Black Chrome configuration provides a darker and more understated rear appearance.
Price: $3,415.00
The Black Chrome option therefore carries a:
$240 premium
over Polished Chrome.
NO PUBLISHED HORSEPOWER CLAIM
SOUL's current product page focuses on:
Exhaust tone
Drone management
Construction
Fitment
Daily drivability
It does not provide a controlled factory-muffler versus Sport-Muffler dyno result.
DasMotoring therefore does not advertise a specific horsepower or torque increase from the Sport Side Mufflers alone.
NO VERIFIED CURRENT WEIGHT FIGURE
SOUL's current Carrera 4S Sport Side Muffler page does not publish a factory-versus-SOUL weight comparison.
The standard narrow-body 996 Carrera Sport Side Mufflers have published weight data, but they are a different physical muffler system.
DasMotoring therefore should not reuse the narrow-body 5.1-lb weight-savings figure for the Carrera 4S product.
NO ECU TUNE REQUIRED
No ECU calibration is required to install the Sport Side Mufflers.
They do not themselves replace:
Catalytic converters
Oxygen sensors
Headers
Engine-management hardware
They are a downstream mechanical exhaust upgrade.
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