Just recently bought a hks hi-power cat back for my '05 wrx, and after researching similar threads i still have a couple questions before installing:
There is talk of a spring type donut gasket/flange thing that needs to be taken off the stock pipe in order for the hks pipe to mate to it correctly. Can anybody elaborate on this with pics if possible?
Is a new gasket needed to replace the spring type donut when its removed? And if so, are new bolts needed?
Anybody who has done a hks hi-power on a wrx themselves, input and comments please.