O2 Sensor Out of Range During Deceleration (Bank 1 Sensor 1)
During engine deceleration with closed throttle (DFCO), the O2 sensor on bank 1 sensor 1 should swing fully lean as the manifold fills with fresh air. Code is set when the swing does not happen — usually a slow or coated sensor.
Affected components
- Oxygen sensor
Common causes
- High likelihood: Sensor slow or coated
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.