WRX Adam

So here's the thing. I've got a 2014 (new shape sti) whose stock exhaust needs replacing as its too quiet.

Now i could take the safe option n go cat back or should i go further?

Here's a stupid question? Does a "full" system remove both cats or just the second one? I ask because my last 2001 wrx had a "full" system but upon inspection, only the second one was removed (my understanding was that both were supposed to go?). It still sailed through its emissions test n when i tried to sell the second cat for scrap, was told it wasn't a proper cat but a "euro" cat. The bloke got a metal rod that passed straight through it as though it was hollow and gave me a couple of quid for it.

So what does it do, is it necessary and when i replace my exhaust should it stay or go if i still want to pass emissions???

Thanks in advance.

WRX Adam

Just discovered that with the older wrx (not sure if this includes the more modern versions) in the uppipe there is a precat, so now I'm wondering if the reason why my old wrx passed emissions with the second cat missing was due to this and therefore if i remove the second cat from my sti, will it fail on emissions?

WRX Adam

Should have mentioned in my last post that older sti's did not have the precat in the uppipe.