What usually causes it
- A failed or worn out rear oxygen sensor
- An exhaust leak near the sensor
- Damaged wiring or a loose plug
- A worn catalytic converter
P2270Starts at: OK to drive, fix when convenient
Rear oxygen sensor stuck on lean (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 air and does not change.
Check this first
Listen for ticking or hissing from the exhaust, which points to a leak, before you buy a new sensor.
What to watch for
- A rotten egg smell from the exhaust
- Poor gas mileage
- A flashing check engine light, which means a bad misfire
Can I keep driving?
We rate P2270 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 P2270
What does P2270 mean?
Rear oxygen sensor stuck on lean (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 air and does not change.
Can I keep driving with P2270?
We rate P2270 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 P2270?
The most common causes, in order: A failed or worn out rear oxygen sensor; An exhaust leak near the sensor; Damaged wiring or a loose plug; A worn catalytic converter.
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.