All fault codes

P0141: O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 2)

LowPowertrainEmissions

Symptoms

  • Check engine light
  • Slightly reduced fuel economy
  • Slow to reach closed-loop operation on cold starts
  • No major driveability issues

Common causes

  • Failed heater element inside the downstream O2 sensor
  • Blown O2 heater fuse
  • Damaged wiring or connector to the sensor
  • PCM driver issue (rare)

What to do?

Check the O2 sensor heater fuse first - a simple fuse replacement is sometimes all that is needed. Inspect the connector for corrosion or melted pins, common on sensors near hot exhaust. If wiring is good, replace the downstream O2 sensor.