P0141O2 Sensor Heater Circuit Bank 1 Sensor 2
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- The downstream oxygen sensor on bank 1 (sensor 2) has an electric heater so it reaches its working temperature quickly. The control module switches the heater on the ground side and checks both the driver voltage against the commanded state and the heater current. GM fails it outside 0.3–2.5 A (two trips; pure circuit faults are P0036–P0038 there); Ford uses P0141 as its general heater circuit code with a current window of roughly 0.22–0.465 A minimum to 3 A maximum depending on sensor supplier. Without heat the sensor signal is useless, so converter monitoring and trim are suspended.
- What you may notice
- Check engine light on (usually after two drive cycles)
- Catalyst monitor readiness not set
- Follow-up codes P0140/P0136 possible
- Likely causes
- LikelyHeater element in the sensor burnt out (replace sensor)
- PossibleHeater supply (fuse, relay) or control wire open
- PossibleShort in the heater (current too high)
- RareConnector corroded, contact resistance
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €50 – €250
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.