O2 Sensor Reference Resistance Out Of Range (Bank 1)
The reference resistance of the wide-band O2 sensor on bank 1 is outside the calibrated range — used by the controller to set the operating point of the pumping cell. Drift here indicates sensor element ageing or contamination.
Affected components
- Oxygen sensor
Common causes
- High likelihood: Sensor element aged or contaminated
Possible symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
Related codes
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.