P0141 — O2 Sensor Heater Circuit (Bank 1, Sensor 2)
Low severityWhat it means
The heater inside the downstream oxygen sensor on bank 1 has failed. This sensor monitors the catalytic converter rather than controlling fuel, so the engine usually runs normally — but the converter cannot be monitored and emissions checks will fail.
Common symptoms
- Check engine light
- No noticeable driveability change in most cases
- Failed emissions inspection
Likely causes
- Failed heater element in the aged sensor
- Blown fuse in the heater circuit
- Damaged wiring or corroded connector
- Rare: engine control unit driver fault
What to check first
- Check the heater circuit fuse
- Inspect wiring and the connector under the car for corrosion or heat damage
- Measure heater resistance at the sensor pins
- Replace the sensor if the heater is open-circuit
Can you keep driving?
Safe to drive; repair it to restore catalyst monitoring and pass inspection.
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