Possible Causes
WARNING: This page is about a different car, the 2002 Nissan Pathfinder and 2002 Infiniti QX4. However, it is still accessible from the selected car via links, so may be relevant.
ECM illuminates MIL and sets DTC P0139 when Bank 1 HO2S 2 response time is too long.
ECM illuminates MIL and sets DTC P0159 when Bank 2 HO2S 2 response time is too long. Possible causes are:
- HO2S 2 circuit open or shorted.
- Poor, loose, corroded or damaged terminal connections.
- Defective HO2S 2.
- Fuel pressure.
- Injectors.
- Intake air leaks.