if i drive my '99 prelude for a couple hundred miles, i notice that my rear bumper starts to turn black from the exhaust....what could be the problem??

 

does it turn black from heat or from smoke of the exhaust

 

I would guess that since you say every couple hundred miles that you can clean it off. Which would mean it's smoke, not the heat. If that is the case you are probobly running extremely rich.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Scrim12 &raquo;</TD></TR><TR><TD CLASS="quote">I would guess that since you say every couple hundred miles that you can clean it off. Which would mean it's smoke, not the heat. If that is the case you are probobly running extremely rich.</TD></TR></TABLE>

 

Do you know if you have a cleared out cat? If you or someone that owned the car before you cleared it out then all that carbon is going to come straight out the tailpipe.

 

You are running rich, the black soot is unburnt fuel. Most dohc vtec engines run rich to prevent detonation. You could have searched and found the answer easily.

 

how would i fix it if that is the case??

 

no i dont know if the cat has been cleard out

 

if you can afford it, put a a/f ratio gauge in your car. that will tell if your runnin rich or not, and just how rich your car is running. but the black residue is most likely from the car running rich, not oil.

 

routine maintenance needed