The oxygen sensors in your 2000 Chevy Silverado inform the drivetrain computer of the oxygen content in the exhaust stream. This information helps the computer better adjust the air/fuel mixture sent into the engine's combustion chambers. The oxygen sensors take a lot of abuse as miles accumulate, and they can fail--particularly as a car rolls past the 100,000 mile mark. If one or more of your 2000 Silverado's oxygen sensors fails, you might notice a drop in fuel economy and engine performance. Ultimately, your Silverado's Check Engine light will glow on your dashboard. Then you can be sure: It's time to change the oxygen sensors, which you can do at home with a few simple tools in a matter of minutes.
Drive your Silverado for about 20 minutes at highway speeds to bring the engine to operating temperature. This will make it much easier to remove the oxygen sensor without damage to the boss threads on the exhaust system where the sensor mounts.
Park your Silverado on level ground and set the transmission to "Neutral." Raise the front of the Silverado with a floor jack, support the Silverado on two safety stands placed under the frame rails, and apply the parking brakes. Block one rear wheels with a chock on either side.
Open the hood and locate the oxygen sensor you need to replace. You may follow the left or right headed pipe that connects to the exhaust manifold toward the rear of the vehicle. You could use a diagnostic scan tool to determine which oxygen sensor has failed, or you can just replace them both and save the trouble of changing the older one when it fails later. You will find a sensor right before the catalytic converter and another one after. The sensor is a small cylinder, about the size of a spark plug, with an electrical wire at the end.
Trace the electrical wire from the sensor to find the connector. Examine the connector and remove the small plastic pin that secures both halves of the connector. Put it in a pocket. Unplug the connector.
Position an oxygen sensor socket on the sensor, unfasten the sensor from the exhaust pipe with a ratchet, and remove the sensor.
Apply a coat of anti-seize compound to the threads of the new sensor, making sure not to touch the tip of the sensor with the compound. Thread the sensor finger tight. Position the sensor socket on the sensor and tighten the sensor to 30 foot-pounds (41 Newton meters) with a torque wrench.
Plug in the sensor electrical connector and secure both halves with the plastic pin.
Lower your Silverado and remove the two chocks.
