P0141: O2 Sensor Heater Circuit (Bank 1 Sensor 2)
The heater inside the downstream oxygen sensor on bank 1 is not working correctly.
What P0141 means
Like the upstream sensor, the downstream oxygen sensor has a small electric heater so it can start working soon after a cold start. P0141 sets when the engine computer sees the bank 1 sensor 2 heater circuit drawing the wrong current or not bringing the sensor up to temperature in time. RepairPal adds that it can set when the rear sensor does not show the expected activity within the required time. The usual cause is a heater element that has burned out inside the sensor, followed by a blown fuse, an open wire or a corroded connector. Because the downstream sensor mainly checks the catalytic converter, there is often no change in how the car drives, but the converter test will not run and the car can fail an emissions inspection. Shops check heater power, ground and resistance, then replace the sensor or repair the circuit. RepairPal also notes that exhaust leaks ahead of the sensor can confuse the diagnosis.
Common symptoms
- Check engine light on
- Usually no driveability change
- Failed emissions test
- Converter monitor will not complete
- Sometimes appears with P0140
Most common causes
- Burned out heater in the downstream oxygen sensor
- Blown heater fuse
- Open or shorted heater wiring
- Corroded connector under the car
- Exhaust leak before the sensor affecting readiness
What to check yourself first
Check the oxygen sensor heater fuse. Unplug the downstream sensor and measure resistance across the two heater pins; an open reading means a bad heater. Clean and inspect the connector for corrosion.
Typical fixes and what they cost
| Fix | Typical cost | Note |
|---|---|---|
| Replace oxygen sensor | $440-$523 | The heater is part of the sensor, so a failed element means a new sensor. |
| Electrical diagnosis to find a wiring or connector fault | $122-$179 | For a fuse, wiring or connector problem. |
| Check engine light diagnosis at a shop | $125-$183 | RepairPal warns sensors are sometimes replaced when the problem is wiring, the converter or an exhaust leak. |
Typical US price ranges for parts and labor, not quotes. Your shop should confirm the cause with a diagnostic before replacing parts.
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