Fuel Control Heated Oxygen Sensors

The main function of the fuel control HO2S is to provide the control module with exhaust stream information in order to allow proper fueling, and to 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 HO2S in a closed loop in order to adjust the fuel injector pulse width. While in 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, the connector, or the terminal are damaged, replace the entire sensor assembly. Do not attempt to repair the wiring, the connector, or the terminals. In order for the sensor to function properly, the sensor must have a clean air reference. This clean air reference is obtained by way of 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 degrades the oxygen sensor performance.