Fuel Control Oxygen Sensors (O2S)

The main function of the fuel control Heated Oxygen Sensor (HO2S) is to provide the control module with exhaust stream information in order to allow proper fueling and maintain emissions within the mandated levels. After the sensor reaches the operating temperature, the sensor generates a voltage inversely proportional to the amount of oxygen present in the exhaust gases.

The control module uses the signal voltage from the fuel control heated oxygen sensors in a Closed Loop in order to adjust the fuel injector pulse width. While in a Closed Loop, the control module can adjust fuel delivery in order to maintain an air-to-fuel ratio which allows the best combination of emission control and driveability.

If the oxygen sensor pigtail wiring, connector, or terminal are damaged, replace the entire oxygen sensor assembly. Do not attempt to repair the wiring, connector, or terminals. In order for the sensor to function properly, the sensor must have a clean air reference. This clean air reference is obtained by the oxygen sensor wires. Any attempt to repair the wires, the connectors or the terminals could result in the obstruction of the air reference. Any attempt to repair the wires, the connectors, or the terminals could degrade oxygen sensor performance.