Catalyst and Exhaust System
Heated Oxygen SensorsThe Compuvalve monitors upstream Heated Oxygen Sensors (HO2S). The upstream heated oxygen sensor (HO2S11) is used to control engine fuel flow. The sensor detects the concentration of oxygen in the exhaust gas and sends a signal to the Powertrain Control Module (PCM) and to the Compuvalve. In a rich condition, the HO2S will output a voltage of 0.6 volt or greater, and in a lean condition a voltage of 0.4 volt or less will be output.
In the event that the HO2S fails, the Malfunction Indicator Lamp (MIL) will be illuminated.