General Information

Component Location





General Description

The downstream heated oxygen sensor is mounted downstream from the Catalytic Converter (worm-up catalytic converter) or in the rear exhaust pipe. The sensor is used to monitor the efficiency of the Catalytic Converter. Because the Catalyst uses the oxygen in the exhaust, the amount of oxygen coming from the converter is less than what entered the converter. The downstream HO2S signal would usually flat line around.6 to.7 volts with a catalyst the is working properly. When the catalyst efficiency drops, sufficient chemical reaction does not take place. Because the oxygen is not used in the chemical reaction, the signal from the rear oxygen sensor will look similar to the front sensor.

DTC Description

If the oxygen storage time for Bank 1 is lower than threshold , the ECM determines that a fault exists and a DTC is stored and MIL (Malfunction Indication Lamp) turns on.

DTC Detecting Condition