Oxygen Sensor: Description and Operation
PURPOSEThe Heated Oxygen Sensor (HO2S) observes the oxygen concentration in the exhaust and sends a signal to the PCM reflecting whether the mixture is too lean or too rich.
LOCATION
Located in the exhaust tube.
OPERATION and CONSTRUCTION
If the mixture has a high concentration of oxygen in the exhaust, a voltage signal of approximately 0.05 volt is sent to the PCM. A voltage signal of approximately 1.2 volt is sent to the PCM if the mixture has low concentration of oxygen in the exhaust. This voltage signal keeps fluctuating between 0.05 and 1.2 volts according to the amount of oxygen present in the exhaust gas. The HO2S is made of ceramic zirconia. For better operational purposes, the HO2S is heated to improve emissions during cold weather operation.