P2273: Oxygen sensor signal biased or stuck rich (bank 2, sensor 2)
The bank 2 oxygen sensor after the catalyst reads rich and does not move. Usually the sensor, its wiring or genuinely too much fuel.
| Code | P2273 |
|---|---|
| System | Engine and transmission |
| Group | P22xx, NOx sensors, oxygen sensors and emissions |
| Type | Generic: it means the same on every make |
| Can you keep driving? | Yes, no rush |
What P2273 means
The sensor after the catalytic converter (sensor 2) checks that the catalyst is working. Here the bank 2 sensor keeps reading rich (little oxygen) even when it should not, for example when you lift off the throttle. Bank 2 is the side opposite cylinder 1, only on engines with two banks.
Most common causes
- Contaminated or faulty downstream oxygen sensor
- Sensor signal wire touching a voltage source
- Moisture or corrosion in the connector
- Engine genuinely running rich (leaking injector, purge valve)
- Engine burning oil or coolant and fouling the sensor
Symptoms
- Engine warning light on
- Engine usually runs as normal
- Possible inspection failure because of the warning light
Can you drive with P2273?
Yes, no rush You can drive as normal; this sensor does not control the engine. If there are also rich mixture codes or a fuel smell, get that checked first to protect the catalyst.
How to check it
Watch bank 2 sensor 2 live when you lift off the throttle while moving: on overrun the injection cuts and the voltage should drop to about 0.1 volts. If it stays high, the sensor or its wiring is the suspect.
How to read and clear P2273 with Final OBD
Plug an OBD2 scanner in under the steering wheel, switch the ignition on and open Final OBD. Under Faults you’ll see P2273 with this same explanation and whether it’s confirmed, pending or permanent.
With Free you read this code with its short description for nothing, and clear it if the engine stores it over standard OBD. With Pro you get the full explanation, how the car was running when it was logged (revs, temperature, load) and clearing in every control unit.
Clearing the code only turns the light off: if the cause is still there, it comes back. Clear it once it’s fixed, and not right before the ITV. It’s all in how to read and clear fault codes and in the ITV and OBD.
Similar codes
- P2269 Water in fuel detected
- P2270 Oxygen sensor signal biased or stuck lean (bank 1, sensor 2)
- P2271 Oxygen sensor signal biased or stuck rich (bank 1, sensor 2)
- P2272 Oxygen sensor signal biased or stuck lean (bank 2, sensor 2)
- P2279 Intake air system leak
- P2293 Fuel pressure regulator 2 performance
- P2299 Brake pedal and accelerator pedal positions incompatible
- P2200 NOx sensor circuit fault (bank 1)
- P2201 NOx sensor circuit range or performance problem (bank 1)
- P2227 Barometric pressure sensor A range or performance problem
- P2228 Barometric pressure sensor A circuit low
P2273 is a generic code, so it means the same on any make, for example on Abarth, Alfa Romeo, Cupra, Jeep, Nissan, Škoda. See what Final OBD does on your car in makes and models.
What does code P2273 mean?
The sensor after the catalytic converter (sensor 2) checks that the catalyst is working. Here the bank 2 sensor keeps reading rich (little oxygen) even when it should not, for example when you lift off the throttle. Bank 2 is the side opposite cylinder 1, only on engines with two banks.
Can you drive with P2273?
You can drive as normal; this sensor does not control the engine. If there are also rich mixture codes or a fuel smell, get that checked first to protect the catalyst.
How do you clear P2273?
With an OBD2 scanner and an app like Final OBD, which clears it for free if it’s stored by the engine control unit. But clearing it only turns the light off: if the cause isn’t fixed, P2273 comes back.
Read it on your car
Final OBD reads the faults of every control unit for free, including each make’s own codes, and with Pro explains each one in plain English. Free clears engine faults at no cost.
Coming soon
Mid to late October 2026
If you want to try it in your car before anyone else, send us your email and we will add you as a tester.
info@finalobd.com