Well I just got my pacemakers installed today (in 44 degree heat, not soo good haha) and I was talking to a mate and an apprentice mechanic and they said my exhaust system would make me lose power because there is not enough back pressure. All it is is the extractors, stock cat and a 2.5 inch pipe all the way back to the tip. No muffler or resonator (as far as I can remember). I've searched a couple of old threads, couldn't find a specific answer. So all I'm asking for is whether that sort of system is fine, both EPA legally and performance wise. If not then I'll most likely go for a Lukey Ultra-Flow muffler and chuck that on. Suggestions? Not interested in a full on debate or criticism about exhausts, I've read and contributed to my fair share of those threads. Straight answers please.