Heated Oxygen Sensor (HO2S)

Sensor monitors the amount of oxygen in exhaust gas. Sensor provides a voltage signal which is used by PCM to adjust air/fuel mixture to obtain optimum air/fuel mixture. The heater portion of this sensor quickly brings sensor to operating temperature. HO2S returns a sweeping return signal which varies between.25 and.75 of a volt. A rich exhaust gas mixture causes high sensor voltage (0.6-10 volt). A lean exhaust gas mixture causes low sensor voltage (0.1-0.3 volt). The PCM monitors signal from sensor and adjusts the air/fuel mixture accordingly.