P0170 VOLKSWAGEN Fuel Trim 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 description Dirty air filter, air filter housing or Mass Air Flow (MAF) sensor, or faulty MAF…