I will try to keep this short. I started hearing a weird kind of rubbing/squeal after I fixed some header leaks, now I am getting a backfire inside the intake after the car warms up a little. the throttle body is coated with a black/brown soot and the car runs like crap (backfiring) at anything over about 1/8 throttle. I can also hear what sound like a miss while cruising at a steady speed. I think the squeal/rubbing noise is coming from the opticrap. at least thats where the noise seems to be coming from. it sounds kind of like a high pitched woot-woot-woot-woot that comes and goes and fluctuates it gets quieter with more engine temp. do I need a new opti? anyone ever have this problem before?