I have 1992 3.1 camaro which I believe is running rich. I have heavy amounts of carbon coming out of my exhaust leaving black residue where ever I park. Does anybody know what could be causing this problem?Please HELP!
(I checked timimg, sensors, and valves. I also had a full tune-up there is no check engine light)

 

Welcome aboard thirdgen.org.

How did you "check" the O2 sensor?

 

This could be a dumb question but if its a new car have u ever checked that cat? cuz usally high carbon is #1.Cat #2.Valve seals #3.Timing and O2 sensor

 

How's your gas mileage?

 

HI ! My gas ant that bad ... But not like it was .. at times you can smell it when it's running ( I changed the throttle sencer , map sencer , o2 sencer ) as time goes it's getting worst .. I don't know ....

 

I'd suspect a leaking fuel injector. Put a pressure gauge on it and see if the pressure falls off quickly when the engine is shut off.

 

Hi ! o2 sencer... Thats the one that goes in exhaust pipe before the cat .. RIGHT .. I replaeced it when I did my exhaust system three years ago ...

 

Ok ... the exhaust system is three years old thats when I did the o2 senser ... the valves leak just little bit , (it mit take a year to see it on a stick)

 

I'll have to let you know about that ... I'll check that ... ( I was thinking bad throttle body) M.F.I

 

As problems like this seem to go...I have to ask, is the residue on the surfaces where youv'e parked by any chance water with black stains/streaks in it, staining the pavement? An exhaust can puke out more water than some folks would think on cold humid days leaving a black puddle. I've had this complaint at the dealerships before.
Unleaded gas by nature leaves a black smeary residue in the tailpipes.