Expert: Sean Halliday - 1/31/2008

Question
My truck is missing very very bad. Its using way too much gas and has pitch black smoke coming out of the tail pipe. I've changed one oxygen censor,the temperature cooling censor, put in new plugs and wires (before the black smoke) and its worst than ever.. What would you recommend?
Thank You

Answer
Running too rich would be the o2 sensor first off but you have changed it so,it could be the fuel pressure regulator.Im assuming all the wires are on the right plugs?You didnt mix them up?Black smoke is way too much fuel getting in the cylinders so its a fuel mix problem.This is controlled by the pcm and fuel regulator also the evap system so you will need to look at all of these.Did you get any check engine lights?This rich running is not good for your engine and i wouldnt recommend driving it too far.