OBD-II code · Powertrain (generic, extended)
P23C2 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.
Is it safe to drive with P23C2?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelySensor element aged
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)
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–1.8 h
- Emissions test
- Likely to fail
- Parts involved
- Nox Sensor B1s3
Related codes
- P23BFNOx Sensor Performance Slow Response Low to High Bank 1 Sensor 3
- P23C0NOx Sensor Performance Slow Response High to Low Bank 1 Sensor 3
- P23C1NOx Sensor Sensing Element Bank 1 Sensor 3
- P23C3Engine Coolant Bypass Valve C Position Sensor Circuit
- P23C4Engine Coolant Bypass Valve C Position Sensor Circuit Low
- P23C5Engine Coolant Bypass Valve C Position Sensor Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.