41) Continuous Memory DTC P0171, P0172, P0174 Or P0175: Fuel System At Corrected Fuel Trim
DTCs P0171, P0172, P0174 and P0175 indicate a problem when adaptive fuel strategy senses a lean or rich condition beyond the minimum or maximum calibrated limit. Possible causes for these faults are:
Excessive fuel pressure, leaking or contaminated fuel injectors, leaking fuel pressure regulator, low fuel pressure or engine running out of fuel or vapory recovery system fault.
Air leaks after MAF sensor, air intake system obstructions, vacuum leaks, PCV system or improperly seated engine oil dipstick.
Leaking gasket, stuck EGR valve or leaking diaphragm or EVR.
Engine oil overfilled, cam timing, cylinder compression or exhaust leaks before or near HO2S.
Inspect engine for obvious defects in specified systems. Repair as necessary