Report: Oxygen Sensor Heater May Fail
Toyota 4Runner Problem
Average Mileage: 123,500 mi (107,000 mi - 140,000 mi)
The heater circuit for the oxygen sensor tends to have a higher than normal failure rate. Failure of the oxygen sensor heater circuit will illuminate the Check Engine Light. The internal oxygen sensor heater cannot be repaired, the failed sensor should be replaced to correct this concern.