P2277O2 Sensor Signal Biased/Stuck Rich (Bank 2, 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
- P2277 is the rich-side counterpart of P2276: the third, post-catalyst sensor on bank 2 does not drop to a lean reading. On such layouts the check normally runs during a fuel cut, when the second catalyst must fill with oxygen before the sensor can respond, so a slow or fouled element shows up here. No manufacturer publishes a threshold for P2277 itself; Jaguar Land Rover lists it among the bank 2 post-catalyst sensor codes of the 2014 to 2016 3.0 supercharged V6 and replaces water-damaged sensors. For reference, VW tests the bank 1 twin P2275 against 0.15 V after 4500 mg of oxygen, and Ford fails a sensor whose lean peak never drops below 0.48 V. A shorted signal wire or oil and coolant fouling are further causes. P2273 is the fault at sensor 2; P0164 a voltage above range.
- What you may notice
- Malfunction indicator lamp on
- No noticeable change in driveability
- Likely causes
- LikelyBank 2 third oxygen sensor contaminated or water-damaged
- RareSignal wire of sensor 3 touching a voltage source
- 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.