O2 Sensor Circuit Range/Performance Bank 2 Sensor 3
The third oxygen sensor on bank 2 (after a second catalyst stage on some vehicles) returns implausible values. Often related to sensor aging or mechanical exhaust leak upstream.
Affected components
- Oxygen sensor
- Exhaust pipe
Common causes
- High likelihood: Sensor aging
- Medium likelihood: Exhaust leak upstream
- 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.