This Borla section replaces the secondary cats on the E9X 335i/335xi. They bolt on to the stock downpipes with factory-style flanges. At the back of this section is an open pipe that can be used with the Borla cat-back mufflers or with another system of your own design (it is not designed to work with the stock exhaust system). Eliminating any part of the stock emissions equipment means this piece is for OFF ROAD USE ONLY.

The cats are a small area of restriction on these cars, so for a track-only car removing the catalytic converter is a must. These also work well when used in conjunction with the Borla cat-back exhaust. These off road track pipes will work on all 335i and 335xi, 2007, 2008, 2009 2010.