ATP stainless steel 3" hi-flow cat option to be used with 3" turbo downpipe P/N ATP-VVW-013 for the Golf/Jetta/Beetle. Replaces the rear "race section" on the original downpipe for an emissions friendly dirct swap. Includes the rear adapter to reduce to correct diameter. Comes with a provision for the second factory oxygen sensor. The hi-flow cat eliminates the engine checklight seen when running the race section