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 P1143 (Bank 1) or P1163 (Bank 2) when maximum and minimum voltage from sensor do not reached specified voltages. Possible causes are:
- Defective HO2S 1 heater.
- Fuel pressure incorrect.
- Poor, loose, corroded or damaged terminal connections.
- Defective injectors.
- Intake air leaks.