Usually an O2 sensor. located on the exaust pipe prior to the muffler.....looks like a spark plug with a wire that comes off the tip and leads into the wire loom.
Most often black smoke is caused by the engine burning oil. The most common cause of burning oil is worn rings on one or more of the cylinders. The fix is to rebuild the engine, honing the walls, and...
A vehicle with black smoke from the exhaust is either running too rich ( fuel air mixture is incorrect ) or burning oil. If your vehicle is older and you keep having to add oil it is probably the...
Black smoke would usually be caused by oil getting into the combustion chamber. check and/or renew oil rings Edit: Oil normally is blue..unburnt fuel would be black
Its a long shot but... If you have a leak in the exhaust before the oxygen sensors, the sensors will think the engine is running lean. The computer will compensate (from incorrect input data) by...
Black smoke is a sign of a vehicle running rich. I would check for a bad fuel pressure regulator, bad fuel injector or very plugged air filter. A fuel pressure test could tell you much.