I have an 02 sti with ppp fitted by the dealer with certificate to prove. I bought it as a used car, am I right in thinking it should only have 1 cat in the exhaust system? Mine looks like it has 2 on it.

Cheers.

 

I believe tThey just remove the centre cat, which is the short section just back from the downpipe. The genuine prodrive de cat also re-uses the heat shield from the OE cat, so so it will look much the same as the original cat pipe did.

 

Fair enough thanks.

 

The STi doesn't have a cat in the up-pipe - so there is only two cats in a std STi.
The PPP then removes the centre section cat as Bryno says, plus the downpipe cat gets swapped with a sports cat.

So yes, your car only has one cat.

Nick

 

as above likely what you think is a second cat in your centre is a resonator
martin