CHECK ENGINE light comes on. When this happens I get code(s)PO171 andPO174
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1999 Ford Explorer Question: What is code PO174 and PO171?
fernando November 29, 2010, 13:42Master
OBD II Code P0171 and P0174 = Fuel System Too Lean (Bank 1 or 2).
There is very nice information about these codes in the RepairPal Encyclopedia; http://repairpal.com/OBD-II-Code-P0171-and-P0174
Answer #2todays tech November 29, 2010, 17:48Journeyman
System too lean bank one and two, likley vacuum leak.
Answer #3DaveJHM November 29, 2010, 22:00Master
Think intake manifold o-rings...if it's a 4.0L SOHC engine.