Catalyst / Bypass
The Catalysts Premium range of DPFs is made using silicon carbide as opposed to cordierite which is used in the standard range of DPFs. Also known as carborundum, it is a material widely used in applications that require a high thermal or strength endurance.

Fits:
Porsche 957 Cayenne 3.0 DIESEL Tiptronic S 1/2009-02/2010
M059D engine (Euro 4 DPF only)
Length*: 680mm
Weight: 6kg
* Lengths are measured flange to flange in a straight line (shortest distance) and should only be used as a guide
Warranty: 3 years manufacturer's warranty
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
955113023GX
The product you are viewing cross references to these numbers
- Porsche 955 Cayenne S 4.5L V8 2003-06
- Porsche 957 Cayenne 3.0L Diesel 2007-10
This is standard replacement secondary Catalytic Converter made out of cordierite.

Fits:
Porsche 957 Cayenne 3.0 DIESEL Tiptronic S 1/2009-02/2010
M059D engine (Euro 4 DPF only)
Length*: 680mm
Weight: 4.6kg
* Lengths are measured flange to flange in a straight line (shortest distance) and should only be used as a guide
Warranty: 2 years manufacturer's warranty
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
955113023GX
The product you are viewing cross references to these numbers
- Porsche 955 Cayenne S 4.5L V8 2003-06
- Porsche 957 Cayenne 3.0L Diesel 2007-10
This is standard replacement primary Catalytic Converter.

Fits:
Porsche 957 Cayenne 3.0 DIESEL Tiptronic S 1/2009-02/2010
M059D engine (1st cat; DPF models)
Length*: 715mm
Weight: 4.7kg
* Lengths are measured flange to flange in a straight line (shortest distance) and should only be used as a guide
Warranty: 2 years manufacturer's warranty
Related reference numbers
Related, superseded, cross reference or alternative numbers for comparison.
95511303700
The product you are viewing cross references to these numbers
- Porsche 957 Cayenne 3.0L Diesel 2007-10
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.