must be lucky with mine, i have a hi flow cat which is gutted and no resonator or anythin, only have a straight thru rear muffler, cars well tuned and i dont get much smoke if any ahtough i get flames at hi rpm back offs and shifting up, pretty nice, felt a bit more free once the cat was gutted cant remember exactly thought the full gain, roughly 10rwhp i think maybe bit more, it went from 472rwhp to 485rwhp. and from under neath just looks like a normal cat
ben...