Possible Causes
WARNING: This page is about a different car, the 2003 Toyota Tacoma. However, it is still accessible from the selected car via links, so may be relevant.
This DTC uses two-trip detection logic. DTC is set when after engine is warmed up and during vehicle driving at engine speed 1500 RPM or more at vehicle speed of 38 MPH or more, A/F sensor output voltage change value is below the regular value against the fuel trim change value, the ECM determines A/F sensor circuit has slow response/deteriorated (2 trip detection logic). Possible causes are:
- A/F sensor circuit is open or shorted.
- Defective A/F sensor.
- Defective A/F sensor heater.
- Defective A/F sensor heater and relay circuit.
- Air induction system malfunction.
- Improper fuel pressure.
- Defective fuel injector.
- Vehicle has run out of fuel.
- Defective EFI main relay.
- Defective ECM.