does the ams downpipe bolt up to the stock cat? also does any test pipe bolt up to the ams catback exhaust?

 

the ams downpipe has a different flange, that only bolts to their high flow cat or test pipe. And with their catback, if I'm not mistaken, would just bolt up to the stock cat, so you would just need to find a test pipe that is a direct stock replacement piece.

 

Yep, the AMS DP will only bolt up to a AMS test pipe or HFC.