Performance Downpipes

Plan on one. Most downpipe listings recommend a supporting tune, several say a check-engine light may occur without one, and the brands quote their gains with proper tuning. Talk to your tuner before you order so the software and hardware match. Our catless vs catted guide covers the details.

The cell number is how many channels per square inch the converter core has. A catless (race) pipe has no converter and flows the most, with the most sound, rasp and smell. A 200-cell pipe keeps an open high-flow core, and a 300 or 400-cell pipe is denser and the most refined, closest to stock manners.

It can. Modern cars use an oxygen sensor after the converter to check that it is working. Remove the converter, or fit a less dense one, and that sensor reads differently, so many listings state that a check-engine light may occur. A tune that accounts for the new hardware is the usual fix.

Catless and high-flow downpipes and other emissions-related parts are intended for off-road and competition use and may not be legal on the street where you live. A high-flow converter is not the same as a certified replacement part, so check your local laws and inspection rules before you buy or install one.

Most downpipes reuse the factory oxygen sensors, so have an O2 sensor socket ready; seized sensors are common on older exhausts. Some pipes add sensor bungs, extensions or heat shields that change how the sensors fit, so check the listing for your part, and inspect the factory clamps and gaskets while everything is apart.

Some performance parts, including many exhausts and downpipes, ship directly from the brand that makes them. Shipping for these is calculated at checkout, and they may arrive separately with their own tracking number. Made-to-order parts show their lead time on the product page. Returns are accepted within 30 days of delivery (unused, uninstalled, original packaging); non-defective partner-brand returns carry a 15% restocking fee, and large items may cost more to send back.