Possible Causes
WARNING: This page is about a different car, the 2003 Toyota Sequoia. However, it is still accessible from the selected car via links, so may be relevant.
These DTCs use two-trip detection logic. DTC is set when ECM detects a response time of 1.1 seconds or more for heated oxygen sensor to change from rich to lean or from lean to rich with engine idling and at normal operating temperature. Possible causes are:
- Heated oxygen sensor circuit is open or shorted.
- Defective heated oxygen sensor.
- Air induction system malfunction.
- Improper fuel pressure.
- Defective fuel injector.
- Defective ECM.