P2274O2 Sensor Signal Biased/Stuck Lean (Bank 1, Sensor 3)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- Sensor 3 exists only where a bank has a third oxygen sensor, usually behind a second catalyst, so that sensor 2 sits between two bricks. P2274 says this last sensor on bank 1 stays lean when it should swing rich. VW's 2014 data books for the CC, Passat and Tiguan 2.0 TSI define it as a rear signal that does not oscillate and stays under about 0.62 to 0.65 V even after the ECM enriches the mixture by 27.9 %. Jaguar Land Rover lists P2274 with the bank 1 post-catalyst sensor codes of the 2014 to 2016 3.0 supercharged V6, blames thermal shock from water on the hot ceramic and fits a new sensor. CARB requires every secondary sensor to be checked for adequate output. P2270 is the same fault one position forward; P0142 and P0146 cover circuit faults and missing activity of sensor 3.
- What you may notice
- Malfunction indicator lamp on
- No noticeable change in driveability
- Likely causes
- LikelyThird oxygen sensor aged or cracked by thermal shock from water
- PossibleExhaust leak ahead of sensor 3 drawing in air
- RareDamaged wiring or connector of sensor 3
- 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: €60 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.