Possible Causes
WARNING: This page is about a different car, the 2003 Toyota MR2. However, it is still accessible from the selected car via links, so may be relevant.
DTC is set when heated oxygen sensor 1 voltage remains at 0.4 volt or more, or 0.55 volt or less during idle, once engine is at normal operating temperature. Possible causes are:
- Heated oxygen sensor 1 circuit is open or shorted.
- Defective heated oxygen sensor 1.
- Air induction malfunction.
- Improper fuel pressure.
- Defective fuel injector.
- Defective ECM.