hi.
got a 09 wrx sedan.
im confused.
thinking of getting catback exhaust.
later, when i get a catted aftermarket downpipe, do i still need a hi flow cat?
or does the catted downpipe bolt directly to the aftermarket cat back exhaust - with no other cat in between the two?

also, does xforce exhaust bolt directly on? or does it need adapters/welding done to fit to stock downpipe.

The cat is in your downpipe. If you buy an aftermarket downpipe with a high flow cat then you're all done. No further cats required.

Most catbacks will bolt up to the factory downpipe without much issue. I had an ultrex, and then Invidia catback on before changing my downpipe later on.

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MY08 WRX 325hp/456nm/18psi E85