Not dumb at all - this forum is all about discovering something new and leaving something for others to benefit from (I learned a thing or two today)
Good info already shared! With our cars the cat (catalytic converter) and downpipe are a single unit. Aftermarket alternatives consist of a downpipe that may be slightly larger in diameter and incorporate a less restrictive cat or no cat at all - in either case you will achieve a less restrictive exhaust flow which in turn will result in a quicker turbo spool and more HP (to what extent is subjective - dynos vary)
A non catted DP will result in a check engine light (CEL) which can only be squashed by a flash tune (piggybacks no) and a catted DP by some companies will not throw a CEL
I really enjoyed my catted DP - while the performance gain was minimal the sound alone was intoxicating
Hope this helps - here's a quick pic I put together - that may help anyone reading this post. It's a pic of an aftermarket catted DP
