P2274 O2 Sensor Signal Biased/Stuck Lean (Bank 1, Sensor 3)

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.

Likely causes

Symptoms

• Malfunction indicator lamp on
• No noticeable change in driveability

Repair estimate

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

Related codes

References: static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov, law.cornell.edu.