Fits 1997 - 2001 Audi A4/Vw Passat with K03, K04, or ATP Elminiator Series Turbos 3" racing downpipe deletes restictive cat immiediately after the turbo on the longitudinally mounted 1.8T. There is no welding or cutting necessary. The downpipe has a large 3" opening to take full advantage of the turbo flow and has provisions for the factory oxygen sensors. Typical gain is 200 to 400 rpm sooner spoolup and 40 ft/lb of wheel torque. HP gain is 10-15 on stock and K04 turbo and 30-40 on GT28RS or larger turbo. Our favorite when used with stock exhaust for ultra quite stealth sound. This part is for offroad use only.