k heres the problem. my brother has a white crx with a b16a in it. after driving for about a week....there are noticable black residue on his bumper that seems to be from the exhaust. any idea on why this is happening?

 

well, if he isn't using the right ecu, or his tune is bad, you are probably running too rich.

 

hes using a p28 chipped ecu....dont know what kinda chip tho