O2 Sensor Signal Biased/Stuck Lean (Bank 2 Sensor 3)
O2 sensor at bank 2 sensor 3 reports a lean reading suspiciously stable for too long. Sensor 3 is typically downstream of the second catalyst on systems with three-stage aftertreatment.
Affected components
- Oxygen sensor
Common causes
- High likelihood: Sensor aged
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.