unburned fuel on rear bumper?

[Deadly BlaZe]

after a few miles of driving i notice that there's this black stuff on my bumper that's coming out of my muffler. im pretty sure this is unburned fuel and also why my gas mileage is bad. does this mean the car is running rich, lean, or wat? any help would be appreciated

 

[marcmsj]

sounds like carbon buildup.. are you running without a cat?

 

[JiveMasterT]

after a few miles of driving i notice that there's this black stuff on my bumper that's coming out of my muffler. im pretty sure this is unburned fuel and also why my gas mileage is bad. does this mean the car is running rich, lean, or wat? any help would be appreciated

thats one of the perks of having a black car... you are going to get that if you dont run with a cat... its carbon build up.

 

[Deadly BlaZe]

thats one of the perks of having a black car... you are going to get that if you dont run with a cat... its carbon build up.

if when you say cat u mean catalytic converter..ofcourse i have one. im guessing that means there's something wrong with it? would a bad o2 senser do that?

 

[JwUoNoG]

What are your fuel mods?

 

[Omega]

Carbon is a byproduct of buring dinosaurs and plants.. a little bit around the exhaust tip(s) is normal. If you have a tip/muffler that is close to or pointing to the bumper, you will see more build up.

Excessive amounts does mean you are running rich, or you have not washed your car in awhile.

 

[marcmsj]

if when you say cat u mean catalytic converter..ofcourse i have one. im guessing that means there's something wrong with it? would a bad o2 senser do that?

a bad o2 sensor would usually make you run rich.. i would test to see if yours is in working order...