Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
I have a 2002 ford f150 4.6L the codes say I'm to lean on both banks. My s.t.f.t. is at -9.7% on both and my l.t.f t. Is at 29% on both banks. The truck is barley running. What could cause this. I can't find a vacuum leak anywhere, the maf sensor seems to be working fine I cleaned the injectors. Changed the plugs, checked the fuel pressure which was good. I just can't figure it out.
smoke test intake and check egr tube going from egr to intake they tend to leak where the 2 bolts mount it to the intake "there should be a calibrated gasket there". also another issue is the imrc controller valves in intake tend to get gummed up and stick shut or stuck open. you will have to peak behind intake and look down at the two rods going to the imrc butterfly valve rod and see if they are sitting loose "not connected to anything on one end".
