Got a 92 F150 with the 5.8 that keeps throwing a code and runs like crap. It develops a bad miss, drinks gas like crazy and has a black smokey exaust but only when the CEL is on. The light will go off on its own, sometimes several times a day and the truck will run great. We replaced the O2 sensor and the truck has new plugs, wires, cap and rotor button. Autozone can't read codes on vehicles this old so anybody got any ideas what the problem might be? I assume something is causing it to run rich, but what? B\G
Pull the vacuum line off of the fuel pressure regulator and see if there's any fuel in there. Same for the evap lines. There should be a charcoal canister on the passenger side near the battery someplace. The vac lines run from there up to the intake... probably one on each side of the throttle body.
You don't need a code reader to check codes. You just run a jumper between two of the pins on the test connector.
