Eighty-Eight Royale FWD V6-3.8L VIN K (1996)
Heated Oxygen Sensor: Testing and Inspection
Heated Oxygen Sensor 1 (HO2S 1)
The heated oxygen sensor (HO2S 1) voltage can be monitored with a scan tool. By monitoring the voltage output of the oxygen sensor, the PCM
calculates what fuel mixture command to give to the injectors (lean mixture-low HO2S voltage = rich command, rich mixture-high HO2S voltage
= lean command).
The HO2S 1 circuit, if open, should set a DTC P0134 and the scan tool will display a constant voltage between 400 - 500 mV. A constant voltage
below 300 mV in the sensor circuit (circuit grounded) should set DTC P0131, while a constant voltage above 800 mV in the circuit should set
DTC P0132 fault in the HO2S 1 heater circuit should cause DTC P0135 to set. The PCM can also detect HO2S response problems. If the response
time of an HO2S is determined to be too slow, the PCM will store a DTC that indicates degraded HO2S performance.
