when my engine is all warmed up to normal temp when i push in the clutch it'll drop to 400-500 rpm then bump up to 800rpm and chill around 800rpm.. i had a test pipe that leaked WAY more and i bogged WAY more, like i couldn't hear my muffler, all i heard was my leak from my test pipe... i have a hi-flow cat now and it helped A LOT but i still have a leak and it happeneds only when i sit for 1-2 mins in one spot.... almost like the exhaust at idle doens't push it through the cat conveter enough cuz of the leak so when i try to go my cat conveter is clogged so when i push in the clutch and rev up to 4-5k its fine after that, like i pushed all the exhaust out and now its fine.... but i dunno, it bugs me very much, so any help on this would be appreciated! thanks!