1997 Explorer SOHC 6 cyl, 4.0L
Changed: Plugs, plug wires, coil pack. Compression test shows compression within 5 psi of eachother. Changed fuel filter, air filter, cleaned MAF sensor. Ran fuel injector cleaner through.
Checked CKP sensor.
Misfiring on cylinders 5 and 6. Also p0174, bank 2 lean.
Only happens when the car is in closed loop. Open loop it is fine. Freeze frame shows everything fine except long term fuel trim on bank 2, which is at ~ +25%.
What I am thinking is my downstream O2 sensor is faulty, causing the ecm to add fuel when it doesnt need it, causing the mixture to become rich. Either that or something with the EGR valve, as it happens in closed loops.
Can anyone point me in the right direction?
Changed: Plugs, plug wires, coil pack. Compression test shows compression within 5 psi of eachother. Changed fuel filter, air filter, cleaned MAF sensor. Ran fuel injector cleaner through.
Checked CKP sensor.
Misfiring on cylinders 5 and 6. Also p0174, bank 2 lean.
Only happens when the car is in closed loop. Open loop it is fine. Freeze frame shows everything fine except long term fuel trim on bank 2, which is at ~ +25%.
What I am thinking is my downstream O2 sensor is faulty, causing the ecm to add fuel when it doesnt need it, causing the mixture to become rich. Either that or something with the EGR valve, as it happens in closed loops.
Can anyone point me in the right direction?