Cooter_76
Sr. Member
- Joined
- May 18, 2004
- Messages
- 863
I have about 600 miles on my Explorer 5.0/4R70W install. The check engine light came on recently. Code reader came up with P1506 - Idle Air Control Overspeed Error. I did a visual check for vacuum leaks and decided to replace the IAC (assuming it was original.) Now I have a P1151 - Lack of Upstream Heated Oxygen Sensor Switch Sensor Indicates Lean Bank 2.
Possible Causes:
- Faulty Upstream Oxygen Sensor Bank 2
- Fuel pressure high or low MAF sensor dirty/defective
- Vacuum leak on engine
- Leaking fuel injector or fuel pressure regulator
- Faulty Powertrain Control Module (PCM)
I installed new 02 sensors during the conversion. Wires and connectors leading from the 02 sensors seem to be in good shape. I do have a K&N style oiled air filter. Don't know if it's possible that oil from the filter has gunked-up the MAF. The only vacuum line that's original to the engine is the molded line that runs under the upper intake manifold.
Has anyone dealt with these specific codes? I suspect a vacuum leak somewhere, but I'm not sure how to diagnose. Start spraying throttle body cleaner around the intake while listening for increased RPM? Is there a better method? Any other suggestions?
Possible Causes:
- Faulty Upstream Oxygen Sensor Bank 2
- Fuel pressure high or low MAF sensor dirty/defective
- Vacuum leak on engine
- Leaking fuel injector or fuel pressure regulator
- Faulty Powertrain Control Module (PCM)
I installed new 02 sensors during the conversion. Wires and connectors leading from the 02 sensors seem to be in good shape. I do have a K&N style oiled air filter. Don't know if it's possible that oil from the filter has gunked-up the MAF. The only vacuum line that's original to the engine is the molded line that runs under the upper intake manifold.
Has anyone dealt with these specific codes? I suspect a vacuum leak somewhere, but I'm not sure how to diagnose. Start spraying throttle body cleaner around the intake while listening for increased RPM? Is there a better method? Any other suggestions?