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!
Hi I was was trying to help out my coworker with his 2002 ford f150 I use to be a ford tech years ago so after he replaced all the parts that he could and still no fix so I checked codes found p0171,p0174 visual inspection for a vaccum leak none smoke test found intake leak replace upper and lower gasket and isolated bolt green found a tsb also I had bank 1 short fuel trim high like 32% and all other trims ok close to 0 after install smoke test again no leaks warm engine recheck fuel trim all are good close to 0 my coworker put over 100 mi on it then went through the car wash check engine back on recheck codes p1131 bank 1 lean check fuel trim bank 1 short trim was 32% and not moving on acceleration all other trims close to zero shut off and check trim now bank 1 short trim 5.5 and going negitive all others close to 0 but test drive back at 32% ac cell hard and on deceleration it starts comming done long trim bank 1 stays close to 0 +/- also he replaced mass air flow sensor both 02 sensor on manifold ,check for exhaust leaks by 02. Ok but had a small leak down stream do the battery have to disconnected after mass air flow replacement , spark plugs,wires,fuel pressure regulator
