K 2500 Yukon 4WD V8-6.0L VIN U (2000)
Oxygen Sensor: Description and Operation
Heated Oxygen Sensors
The main function of the precatalyst Heated Oxygen Sensor (HO2S) is to provide the PCM with exhaust stream information in order to maintain proper
fueling to hold emissions within acceptable levels. These oxygen sensors are always located between the exhaust manifold and the catalytic converter.
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 PCM 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 PCM 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,
the connector, or the terminals. In order for the sensor to function properly, the sensor must have a clean air reference provided to it. This clean air
reference is obtained by way of the oxygen sensor wires. Any attempt to repair the wires, connectors, or terminals could result in the obstruction of the
air reference. Any attempt to repair the wires, connectors, or terminals could degrade oxygen sensor performance.
