Performance Exhaust Systems
Test Pipes & Cat-Bypass Pipes
Short replacement sections for named applications, described by what they fit and how they are built.
Test pipes and cat-bypass pipes are the short replacement sections of the front end: a pipe that takes the place of a catalyst section in the line, built to the application's flange pattern and length. They appear in the company's catalogue as items for specific applications rather than as a range of their own, and they are specified the same way — by application, construction and fitment.
The documented examples are Porsche applications: a test pipe for the 991.2 Carrera with the PSE exhaust, and a secondary cat-bypass pipe for the Cayenne 958.2. Other applications follow the downpipe family's fitment logic and are confirmed on inquiry.
- Named applicationsPorsche applications documented
- SS304 constructionSame benches as downpipes
- Fitment factsApplication, joints, hardware
- Catalogue itemsListed per application
The Documented Porsche Applications
The 991.2 Carrera PSE item is a test pipe built for that car's factory sport exhaust layout: flange pattern, length and joint positions taken from the original section it replaces. The Cayenne 958.2 item is a secondary bypass pipe, again built to the application's own dimensions.
Both are catalogue items with the application named in the listing. That naming is the specification: a test pipe is not a universal part.
Construction and Hardware
Construction matches the downpipe family: SS304 tube, mandrel bent where the routing bends, TIG welded on the application fixture, flange faces machined after welding, and sensor bosses placed from the original part where the application carries them. Sizes sit in the family's 3-inch, 3.5-inch and 4-inch classes.
Hardware is the joint hardware of the application — flanges, V-band joints and gaskets as the car uses them — confirmed item by item in the inquiry reply, because the contents differ by application.
Confirming an Application
Send the vehicle, model year and the section you are replacing, with a photograph of the original section if the car is a variant. The reply confirms whether the application is a catalogue item, an adaptable fixture or a development job, and quotes on that basis.
Ask about test pipes and cat-bypass pipes for your vehicle
Send your vehicle, engine and model year. The test pipes and cat-bypass pipes options that fit are confirmed first, then quoted with finishes and hardware.
Send an Inquiry