P0171 2003 FORD ESCORT System Too Lean Bank 1
Possible causes – Intake air leaks– Faulty front heated oxygen sensor– Ignition misfiring– Faulty fuel injectors– Exhaust gas leaks– Incorrect fuel pressure– Lack of fuel– Faulty Mass Air Flow (MAF) sensor– Incorrect Positive Crankcase Ventilation (PCV) hose connection Tech notes