truck passed emissions a few months ago but lately has degraded rapidly...
sometimes throws too rich code..
truck runs great at 1/2 to wide open throttle, can even do alot of towing on the highway.. but.. 80% of the time.. in the city.. it idles like s*it and when you feed it gas off the line you can hear the truck backfire and not really go anywhere.. if you floor the pedal the truck takes off..
sometimes this clears up and the truck runs great at small throttle openings...
could it be the electric egr? tps? where to start...
thanks