Running rich
I have a 94 Prelude simple mod's. I know my car is running rich my whole bumper is covered with the black smoke or whatever this is anyways I went to clean the inside of the exhaust out and there was black shit everywhere I didn't try to get water all up in the exhaust and I cleaned it out as good as I could and my exhaust was loud as fuck, louder then I've ever heard it before I was wondering why this happened?? Also I'm pretty sure I'm running rich because of my o2 censor is this a good assumption I'm pretty sure there is a way to check it by using a voltage meter or something like that and normal it should be at about 0.7v.