P0141Powertrain
Powertrain · SAE
O2 sensor heater circuit (bank 1, sensor 2)
Meaning
The control unit detects a fault in the heater circuit of the downstream oxygen sensor on bank 1. The heater brings the sensor quickly up to operating temperature.
Common causes
- Open or failed sensor heater element
- Blown heater-circuit fuse
- Damaged or corroded heater wiring or connector
- Faulty heater supply relay
- Incorrect heater-circuit ground or supply
Symptoms
- Check-engine light on
- Slightly higher fuel consumption
- Catalyst monitor struggling to complete
- No obvious drop in performance
Severity
Minor: driving is not affected, but catalyst diagnosis is less reliable and the car may fail an emissions test.
What to do
- Measure the downstream sensor heater element resistance and compare it with specification
- Check the heater-circuit fuse and supply
- Inspect the heater wiring, connector and ground
- If the heater element is open, replace the downstream oxygen sensor