T3 High Flow_cat???

[audi_a4_turbo]

well i got a t3 setup on my a4 one lil probalem, where do i put my high flow cat, and what brand should i use, since the stock cat got replaced with a test pipe, what makes more power, downpipe first then cat or cat then downpipe coming from the turbo.

[AudiA4_20T]

why do you need one?

[B5A4Kevin]

you would make most hp running Test Pipe into Down Pipe, but most catalysts are placed close to the turbo, to aid in warmup. subaru's come with an oem up pipe with a catalytic converter upstream of the turbo. as you would assume, they run into the problem of the shit flaking off and hitting the turbine at full boost.

[audi_a4_turbo]

cuz of where i live, we do emission test every 2 years, plus when i ran a test pipe on my k04 setup my car used to shoot out alot of smoke from my exhaust.

[slideitsidewayz]

the test pipe makes more power hands down. its something like 10-15hp increase for k03 and 30-40hp increase for big turbo apps...thats what i read off ot the atp test pipe atleast and thats what im running. it should go turbo, cat/test pipe, down pipe, exhaust.