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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