Draft guidance: awaiting Claude spot-check, qualified-mechanic review and named-editor approval. Do not use a fault code alone to replace parts.
P0141: Oxygen sensor heater circuit malfunction, Bank 1 Sensor 2
The computer has detected an electrical problem with the heater for the downstream Bank 1 sensor.
What P0141 means
The computer has detected an electrical problem with the heater for the downstream Bank 1 sensor. It is a heater-circuit code, not proof that the catalytic converter has failed, and it does not automatically require a new sensor.
Can I still drive?
It is usually reasonable to make a short diagnostic journey if the light is steady and the car behaves normally. Repair should still be scheduled because the sensor may activate too slowly after a cold start, affecting emissions monitoring. Stop for severe rough running, stalling or a flashing warning.
Symptoms
- Engine-management light
- No noticeable drivability change
- Failed emissions or readiness test
- Delayed downstream-sensor activity after a cold start
Common causes
- Open or shorted heater element
- Blown fuse or missing heater supply
- Heat-damaged or high-resistance wiring and connector
- Missing earth or computer-controlled return
- Rare engine-control-module driver fault
Safe first checks
- Read all codes and inspect the cold downstream harness for exhaust heat damage. Check only the specified heater fuse. If a correct fuse blows again, do not keep replacing it; have the short located. Heater power, control and cold resistance must be tested against the right wiring diagram and factory limits.
Typical UK fix cost
About £90–£320 for diagnosis and a common heater-circuit repair. A fuse or local wiring fix may cost less, while an integrated heated-sensor replacement commonly falls around £110–£266 before access complications.
Related models
This is a generic OBD-II code used across many makes and models. The exact test thresholds, component layout and repair route vary by engine and manufacturer, so check vehicle-specific technical information before ordering parts.
Related fault codes
- P0138: Oxygen sensor circuit high voltage, Bank 1 Sensor 2
- P0140: Oxygen sensor circuit no activity detected, Bank 1 Sensor 2
- P0171: Fuel-trim system too lean, Bank 1
- P0172: System too rich (Bank 1)
Sources
A diagnostic trouble code identifies a system or circuit to investigate. It does not prove that a named part has failed. Preserve freeze-frame data and seek a vehicle-specific diagnosis before clearing the code.