O2 Sensor Signal Stuck Rich (Bank 2, Sensor 2)
The downstream oxygen sensor on bank 2 reports a constant rich signal during a forced-lean command. Suggests a failed downstream sensor or a sensor contaminated by oil/coolant from upstream engine wear.
Affected components
- Oxygen sensor downstream
Common causes
- High likelihood: Downstream sensor failed stuck rich
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.