NOx Sensor Delayed Response High to Low Bank 1 Sensor 3
Same as P23C0 with a measurable delay before the sensor begins to track falling levels - the start of the response is delayed, not just the slope.
Affected components
- Nox sensor b1s3
Common causes
- High likelihood: Sensor element aged
Possible symptoms
- Check engine light or NOx warning on
- AdBlue/DEF level or quality warning
- Possible no-start countdown after ignore period
- Failed emissions inspection (NOx)
Diagnostic notes
- The malfunction indicator lamp may illuminate
- This code can affect emissions
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.