yo wats goin, my buddy just picked up his 2001 s4, and is getting and exhaust system, i think hes goin with autospeed, the thing is though, wen we order his downpipe, do we just need to buy downpipes, or do we need testpipes and cats?

peaace

 

The autospeed DPs come with cats. I got 200 cell metallic cats with mine so there is no need for test pipes.