What usually causes it
- A failed rear oxygen sensor
- Fuel or coolant contamination of the sensor
- Damaged wiring or a shorted wire
- An engine running rich, with extra fuel in the exhaust
P2271Starts at: OK to drive, fix when convenient
Rear oxygen sensor stuck on rich (bank 1, sensor 2)
The oxygen sensor checks the exhaust. Sensor 2, after the catalytic converter (the exhaust part that cleans the fumes), keeps reporting too much fuel and does not change.
Check this first
Look at the wires going to the sensor for melted or damaged spots once the exhaust is cool.
What to watch for
- A strong smell of gas or black smoke
- A rotten egg smell from the exhaust
- A flashing check engine light, which means a bad misfire
Can I keep driving?
We rate P2271 as OK to drive, fix when convenient, as a starting point. Keep an eye on the signs below. If the light starts flashing, stop driving soon.
Quick answers about P2271
What does P2271 mean?
Rear oxygen sensor stuck on rich (bank 1, sensor 2). The oxygen sensor checks the exhaust. Sensor 2, after the catalytic converter (the exhaust part that cleans the fumes), keeps reporting too much fuel and does not change.
Can I keep driving with P2271?
We rate P2271 as OK to drive, fix when convenient, as a starting point. Keep an eye on the signs below. If the light starts flashing, stop driving soon.
What usually causes P2271?
The most common causes, in order: A failed rear oxygen sensor; Fuel or coolant contamination of the sensor; Damaged wiring or a shorted wire; An engine running rich, with extra fuel in the exhaust.
Estimates only. A mechanic should confirm. The same code can mean slightly different things on different cars; the app explains it for your exact year, make, model and mileage.