Diagnostic Aids

DTC is usually set by contamination. Contamination can be caused by fuel, improper use of RTV, engine oil or coolant. Repair cause of contamination first before replacing oxygen sensor.

An intermittent condition may be caused by poor connection, rubbed-through insulation, or a broken wire inside insulation. Check PCM harness connectors for backed-out terminals, improper mating, broken locks, improperly formed or damaged terminals, or poor terminal-to-wire connections before component replacement.