P22A2NOx Sensor Circuit Intermittent (Bank 1 Sensor 2)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P22A2 describes a rear NOx sensor on bank 1 whose measuring circuit reports faults that come and go rather than staying present. Smart NOx sensors pass the state of that circuit (open wire, short or no error) to the engine computer over CAN, so brief, repeated fault reports fit this code. No manufacturer publicly documents a threshold for P22A2. The only trace is a Ford notice for 2015 to 2016 6.7L Super Duty trucks (SSM 45920, NHTSA index only) explaining that the code may stay stored after the actual fault has been repaired; CARB requires NOx sensors to be monitored continuously for circuit faults. Look for loose terminals, heat-damaged cable along the exhaust and water in the connector. P229E is the steady fault, P2204 the same pattern at the front sensor.
- What you may notice
- Malfunction indicator lamp that may go out and return
- Downstream NOx value dropping out briefly
- Code remains stored after the root fault is fixed
- Likely causes
- LikelyLoose or corroded terminals at the outlet NOx sensor connector
- PossibleHarness along the exhaust damaged by heat or vibration
- PossibleSporadic internal fault in the sensor module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €50 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.