O2 Sensor Circuit Range/Performance Bank 1 Sensor 2
The rear oxygen sensor on bank 1 does not show the expected slow steady-state behaviour after the catalyst. Either the sensor is degraded or the catalyst itself behaves abnormally.
Affected components
- Oxygen sensor
- Catalytic converter
Common causes
- High likelihood: Sensor aging
- Medium likelihood: Catalyst aging
- Low likelihood: Sensor element aged beyond calibration window
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
- A drive cycle may be required after repair
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.