Catalyst / Bypass
DesignTek Exhaust manifold / header with catalyst bypass.
Price is for PAIR.

Fits:
Porsche 987.2 Boxster 2.9L / 3.4L 2009-12
Porsche 987C.2 Cayman 2.9L / 3.4L 2009-12
NOTE: Sports catalytic converters and bypass pipes do not have type approval and are not legally permitted for use on vehicles manufactured after 1st March 2001 in the United Kingdom. They are not MOT compliant and must not be used on public roads. These components are intended for race and track use only. If you are located outside the UK, please consult your local laws and regulations to ensure compliance.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
3606109876
The product you are viewing cross references to these numbers
- Porsche Boxster 987 MKII 2.9L 2009-2012
- Porsche Boxster S 987 MKII 3.4L 2009-2012
- Porsche Cayman 2.9L 987C MKII 2009-12
- Porsche Cayman S / R 3.4L 987C MKII 2009-12
Sold as a pair - left and right
Fits:
Porsche 981 Boxster - 2012 to 2016
Porsche 981 Boxster S - 2012 to 2016
Porsche 981 Boxster GTS - 2012 to 2016
Porsche 981 Boxster Spyder - 2016
Porsche 981 Cayman - 2013 to 2016
Porsche 981 Cayman S - 2013 to 2016
Porsche 981 Cayman GTS - 2013 to 2016
Porsche 981 Cayman GT4 - 2016
Made from SS304L lightweight stainless steel these exhaust manifolds offer reduced back pressure with higher flow
- Performance gains of 20hp minimum and 20nm
- Improved throttle response
- Improved exhaust note with no drone, resonation or vibration
- Direct fit no remap required but recommended
- No CEL
- Heat shielded to reduce radiant heat and speeds up exhaust gas velocity
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
9M81113211
The product you are viewing cross references to these numbers
- Porsche Boxster 981 2.7L 2012-16
- Porsche Boxster 981 S / GTS 3.4L 2012-16
- Porsche Boxster 981 Spyder 3.8L 2016
- Porsche Cayman 2.7L 981 2013-16
- Porsche Cayman S / GTS 3.4L 981 2013-16
- Porsche Cayman GT4 3.8L 2015-16
Fits:
Porsche 987.2 Boxster / Boxster S - 2009 to 2012
Porsche 987.2 Boxster Spyder - 2009 to 2012
Porsche 987.2 Cayman / Cayman S - 2009 to 2012
Porsche 987.2 Cayman R - 2009 to 2012
987.2 Equal length exhaust manifold with catalytic converter.
- Reduced back pressure with higher flow
- Made from SS304L lightweight stainless steel
- Performance gains of 15hp minimum and 20nm
- Improved throttle response
- Improved exhaust note with no drone, resonation or vibration
- Direct fit no remap required but recommended
- No CEL (Check Engine Light)
- Heatshieded to reduce radiant heat and speeds up exhaust gas velocity
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
9M87113101
The product you are viewing cross references to these numbers
- Porsche Boxster 987 MKII 2.9L 2009-2012
- Porsche Boxster S 987 MKII 3.4L 2009-2012
- Porsche Cayman 2.9L 987C MKII 2009-12
- Porsche Cayman S / R 3.4L 987C MKII 2009-12

Fits:
Porsche 987 Boxster 2005- 08/2008
Porsche 987C Cayman 2006- 08/2008
DesignTek sports headers and 200 cell high flow cats for throaty sports car sound, but not too loud for every day driving, manufactured from extra heavy duty stainless steel, which eliminates the splitting, cracking and annoying resonance.
Coating: 40g
Cells: 200cpsi
Please note: These sport cats will make your car sound louder than with stock cats. If you have ,or intend to install sport silencers, you may find the car is a bit loo loud. We recommend to use one sport exhaust component if you are concerned about decibel levels.
NOTE: Sports catalytic converters and bypass pipes do not have type approval and are not legally permitted for use on vehicles manufactured after 1st March 2001 in the United Kingdom. They are not MOT compliant and must not be used on public roads. These components are intended for race and track use only. If you are located outside the UK, please consult your local laws and regulations to ensure compliance.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
3606109874
The product you are viewing cross references to these numbers
- Porsche Boxster 987 2.7L 2005 -08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08
Fits:
Porsche 987 Boxster 2005- 08/2008
Porsche 987C Cayman 2006- 08/2008
Please note: This is a set of headers with catalyst bypass. After the installation of this product the emission light might come on your dash. To remove it you might need to install the lambda sensor extensions.
NOTE: Sports catalytic converters and bypass pipes do not have type approval and are not legally permitted for use on vehicles manufactured after 1st March 2001 in the United Kingdom. They are not MOT compliant and must not be used on public roads. These components are intended for race and track use only. If you are located outside the UK, please consult your local laws and regulations to ensure compliance.
Please note:
On the video below customer has fitted our headers and sport silencer with secondary cat bypasses. The car on the video has no cats at all!
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
3606109875
The product you are viewing cross references to these numbers
- Porsche Boxster 987 2.7L 2005 -08/08
- Porsche Boxster 987 S 3.2/3.4L 2005-08/08
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08


Reconditioned units are sold on an exchange basis, A surcharge of £1120.80 will be held and then refunded when the old one is returned.

Fits:
Porsche 987 2.7L Boxster M96.25 Engines
Porsche 987 2.7L Cayman M96.25 Engines
Click 'Zoom in' for large parts diagram.
Diagram ref no 2
Please note:
Reconditioned exhaust manifolds are sold on an exchange basis, A surcharge of £477.00 will be held and then refunded when the old one is returned.
- The surcharge for this reconditioned part will be refunded when the exchange unit is received and approved by us and the relevant manufacturer.
- Please note, surcharge refunds often take an average of 6 to 8 weeks to be approved by the manufacturer.
- Acceptance of the exchange part is at the manufacturer's discretion, based on the part being fit for reconditioning.
- All surcharges and exchanges are subject to our terms and conditions.
PLEASE NOTE:
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
98711310
The product you are viewing cross references to these numbers
- Porsche Boxster 987 2.7L 2005 -08/08
- Porsche Cayman 2.7L 987C 2006-08


Exhaust manifold with catalytic converter. Reconditioned unit with deposit charge. Refundable on return of old unit.

Fits:
Porsche 987 Boxster 2007-08 M97.20 Engines
Porsche 987 Boxster S 2005-08 M97.21 / M97.22 Engines
Porsche 987C Cayman / Cayman S 2006-08 M97.21 / M97.22 Engines
Click 'Zoom in' for large parts diagram.
Diagram ref no 2
- Porsche Boxster 987 2.7L 2005 -08/08
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08
In case you need to relocate your existing lambda probe because it's not in the right location. Welding and cutting specialist required.
Fits:
Many Porsche vehicles. Universal kit.
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
100390100392
The product you are viewing cross references to these numbers
- Porsche 964 (911) C2 1989-93
- Porsche 964 (911) C4 1989-93
- Porsche 964 (911) RS 3.6L 1991-93
- Porsche 964 (911) RS 3.8L 1991-93
- Porsche 964 (911) TURBO 3.3L 1991-93
- Porsche 964 (911) TURBO 3.6L 1991-93
- Porsche 993 (911) C2 1994-97
- Porsche 993 (911) C4 1994-97
- Porsche 993 (911) RS 1994-97
- Porsche 993 (911) C2S 1994-97
- Porsche 993 (911) C4S 1994-97
- Porsche 993 (911) TURBO 1994-96
- Porsche 993 (911) GT2 1994-97
- Porsche 993 (911) TURBO S 1994-97
- Porsche 996 C2 3.4L 1997-08/01
- Porsche 996 C4 3.4L 1997-08/01
- Porsche 996 C2 3.6L 09/01-2005
- Porsche 996 C4 3.6L 09/01-2005
- Porsche 996 C4S 3.6L 09/01-2005
- Porsche 996 TURBO 2000-05
- Porsche 996 GT2 2001-05
- Porsche 996 GT3 MKI 1999-02
- Porsche 996 GT3 MKII 2003>>
- Porsche 996 GT3 RS 2003-04
- Porsche 997 MK1 Carrera 2 3.6L 2005-08
- Porsche 997 MK1 Carrera 2S 3.8L 2005-08
- Porsche 997 MK1 Carrera 4 3.6L 2005-08
- Porsche 997 MK1 Carrera 4S 3.8L 2005-08
- Porsche 997 MK1 TURBO 2007-09
- Porsche 997 MK1 GT3 2007-09
- Porsche 997 MK1 GT2 2007-09
- Porsche 997 MKII Carrera C2 3.6L 2009-12
- Porsche 997 MKII Carrera C4 3.6L 2009-12
- Porsche 997 MKII Carrera C2S 3.8L 2009-12
- Porsche 997 MKII Carrera C4S 3.8L 2009-12
- Porsche 997 MKII GT3 2010-11
- Porsche 997 MKII Turbo 2010-13
- Porsche 997 MKII GT2 RS 2011-13
- Porsche 991.1 Carrera C2 3.4L (350Bhp) 2012-16
- Porsche 991.1 Carrera C2S 3.8L (400Bhp) 2012-16
- Porsche 991.1 Carrera C4 3.4L (350Bhp) 2012-16
- Porsche 991.1 Carrera C4S 3.8L (400Bhp) 2012-16
- Porsche 991.1 Turbo 3.8L (520bhp) 2014-16
- Porsche 991.1 Turbo S 3.8L (560Bhp) 2014-16
- Porsche 991.1 R 4.0L (500 Bhp) 2016
- Porsche 991.1 GT3 3.8L (475Bhp) 2014-16
- Porsche 991.1 GT3 RS 4.0L (500Bhp) 2015-16
- Porsche 991.2 Carrera 2 3.0L (370 Bhp) 2016-19
- Porsche 991.2 Carrera 2S 3.0L (420 Bhp) 2016-19
- Porsche 991.2 Carrera 4 3.0L (370 Bhp) 2016-19
- Porsche 991.2 Carrera 4S 3.0L (420 Bhp) 2016-19
- Porsche 991.2 Cabriolet 2 3.0L (370 Bhp) 2016-19
- Porsche 991.2 Cabriolet 2S 3.0L (420 Bhp) 2016-19
- Porsche 991.2 Cabriolet 4 3.0L (370 Bhp) 2016-19
- Porsche 991.2 Cabriolet 4S 3.0L (420 Bhp) 2016-19
- Porsche 991.2 Targa 4 3.0L (370 Bhp) 2016-19
- Porsche 991.2 Targa 4S 3.0L (420 Bhp) 2016-19
- Porsche 991.2 Turbo Coupe 3.8L (540 Bhp) 2016-19
- Porsche 991.2 Turbo S Coupe 3.8L (580 Bhp) 2016-19
- Porsche 991.2 Turbo Cabriolet 3.8L (540 Bhp) 2016-19
- Porsche 991.2 Turbo S Cabriolet 3.8L (580 Bhp) 2016-19
- Porsche 991.2 Speedster 4.0L (510Bhp) 2019
- Porsche 991.2 GT3 4.0L (500 Bhp) / GT3 RS 4.0L (520 Bhp) 2017-19
- Porsche 991.2 GT2 RS 3.8L PDK (700 bhp) 2018-19
- Porsche 992.1 Carrera 2 3.0L 2019-24
- Porsche 992.1 Carrera 4 3.0L 2019-24
- Porsche 992.1 Carrera 2 Cabriolet 3.0L 2019-24
- Porsche 992.1 Carrera 4 Cabriolet 3.0L 2019-24
- Porsche 992.1 Carrera 2S 3.0L 2019-24
- Porsche 992.1 Carrera 4S 3.0L 2019-24
- Porsche 992.1 Carrera 2S Cabriolet 3.0L 2019-24
- Porsche 992.1 Carrera 4S Cabriolet 3.0L 2019-24
- Porsche 992.1 Targa 4 3.0L 2020-24
- Porsche 992.1 Targa 4S 3.0L 2020-24
- Porsche 992.1 Speedster 4.0L 2019-24
- Porsche 992.1 Turbo 3.8L 2020-24
- Porsche 992.1 Turbo S 3.8L 2020-24
- Porsche 992.1 Turbo Cabriolet 3.8L 2020-24
- Porsche 992.1 Turbo S Cabriolet 3.8L 2020-24
- Porsche 992.1 GT3 4.0L / 992 S/T 4.0L 2021-24
- Porsche Cayman 2.7L 987C 2006-08
- Porsche Cayman S 3.4L 987C 2005-08
- Porsche Cayman 2.9L 987C MKII 2009-12
- Porsche Cayman S / R 3.4L 987C MKII 2009-12
- Porsche Cayman 2.7L 981 2013-16
- Porsche Cayman S / GTS 3.4L 981 2013-16
- Porsche Cayman GT4 3.8L 2015-16
- Porsche Cayman 718 2.0L Manual (300Bhp)
- Porsche Cayman 718 2.0L PDK (300Bhp)
- Porsche Cayman S 718 2.5L Manual (350Bhp)
- Porsche Cayman S 718 2.5L PDK (350Bhp)
- Porsche Cayman T 718 2.0L Manual (300Bhp)
- Porsche Cayman T 718 2.0L PDK (300 Bhp)
- Porsche Cayman GTS 718 2.5L Manual (365 Bhp)
- Porsche Cayman GTS 718 2.5L PDK (365 Bhp)
- Porsche Cayman GTS 718 4.0L Manual (400 Bhp)
- Porsche Cayman GTS 718 4.0L PDK (400 Bhp)
- Porsche Cayman GT4 718 4.0L / GT4 RS 718 4.0L
Exhaust Catalytic Converters & Bypass Pipes – Performance, Efficiency & Flow Control
The catalytic converter plays a crucial role in your Porsche’s exhaust system, reducing harmful emissions while maintaining optimal exhaust flow. Positioned between the exhaust manifold and silencer, it converts toxic gases such as carbon monoxide, hydrocarbons, and nitrogen oxides into less harmful emissions before they exit the tailpipe.
At Design911, we offer a complete range of catalytic converters and bypass pipes for Porsche vehicles. Our manufacturer-quality converters ensure reliable emission control and long-term performance, while our bypass options are designed for track or performance use, optimising exhaust flow for maximum power and throttle response.
Whether you’re maintaining your Porsche to meet emissions standards or upgrading for improved exhaust performance, our selection includes both direct-fit converters and performance bypass kits built from high-grade stainless steel for strength, corrosion resistance, and durability.
What Do Catalytic Converters & Bypass Pipes Do?
A catalytic converter uses a fine mesh of precious metals to trigger chemical reactions that break down pollutants. The bypass alternative eliminates restriction in the exhaust flow, improving performance in non-emissions-controlled environments such as track driving.
Core Functions:
- Converts
toxic exhaust gases into environmentally friendly emissions.
- Maintains
exhaust back pressure for engine efficiency.
- Reduces harmful NOx, CO, and HC emissions.
- Supports smoother engine performance and throttle control.
- Bypass versions enhance exhaust flow and improve power output for track cars.
Upgrading to a performance-grade system ensures your Porsche continues to meet emission requirements — or achieves greater flow and responsiveness for motorsport applications.
Why Do Catalytic Converters Fail?
Catalytic converters are exposed to extreme heat, unburnt fuel, and contaminants — all of which can degrade their performance over time.
Common Causes of Failure Include:
- Carbon
or oil buildup blocking the internal honeycomb.
- Thermal
damage from overheating or rich fuel mixtures.
- Physical
damage from road debris or misfiring engines.
- Corrosion
due to moisture and exhaust condensation.
- Age-related wear reducing catalytic efficiency.
A failing converter can cause reduced engine power, poor
fuel economy, rattling sounds, or a check-engine light. Replacing it
restores emissions compliance, performance, and exhaust efficiency.
Why Replace or Upgrade
with Precision-Engineered Components?
Replacing a failing converter or upgrading to a bypass pipe ensures your Porsche maintains peak performance and reliability.
Key Benefits:
- Restores optimal emissions performance and efficiency.
- Improves exhaust flow and throttle response.
- Reduces engine stress and fuel consumption.
- Durable stainless-steel construction for longevity.
- Direct-fit
compatibility for Porsche 911, Cayman, Boxster, Panamera, Macan
and more.
- Performance bypass options available for track and tuning applications.
Whether you want emissions compliance or maximum flow for competition use, our parts deliver reliability, precision, and performance.
Highlights:
- Direct-fit catalytic converters and bypass pipes for Porsche models.
- Precision-engineered for optimal flow and reduced emissions.
- Built from heat-resistant stainless steel for durability.
- Bypass pipes for performance tuning and track applications.
- Restores power, efficiency, and exhaust sound balance.
- Available for classic and modern Porsche vehicles.