Would a perrin or greddy catch can be a good upgrade for my STi?? Sites that carry these say they will increase the life of the engine by taking the oil out of the intake and that the upgrade will also boost the hp performance of the engine. Is a catch can a good upgrade idea???

You will need 2 of those.

1 is pointless, since STi's have 2 hoses coming from each head making it 4 hoses total.

2 1/2" and 2 5/8".

You cannot T them all into 1 or even 2 hoses or you will blow your cam/main oil seals out.

I recommend not doing this mod, unless you get a larger catch tank and run proper diameter hoses without reducing it.

thanks for the advice :cool: