P2207
NOx Sensor Circuit Range/Performance (Bank 2)
The bank 2 NOx sensor returns values outside the expected range for the operating point — for example a non-zero reading at engine off or unchanged values during load changes.
- Check engine light: Yes
- Emissions related: Yes
- Repair difficulty: medium
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)
Common causes
Ordered by how often each turns out to be the cause.
- Sensor drift due to ageingCommon
- Sensor contaminated with soot or condensatePossible
- Sensor element aged beyond calibration windowLess likely
Parts involved
- NOX Sensor B2
P2207 is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.