The 2003 Chevrolet Tahoe is equipped with either a 4.8-liter V8 engine or a 5.3-liter V8 engine. With each engine option, there are two oxygen sensors in the exhaust system. Install new oxygen sensors in your Tahoe when you notice a significant decrease in fuel mileage or poor idling. Change the sensors at home to save the cost of a service shop. Buy oxygen sensors from an auto parts retailer or Chevrolet dealership.
Lift your Tahoe with a jack and position the truck on a set of jack stands so you can comfortably work under it.
Locate the oxygen sensor protruding from the exhaust pipe just before or just beyond the catalytic converter. Disconnect the electrical connection from the top of the sensor by pulling the connector apart. Remove the sensor with an oxygen sensor socket and ratchet.
Insert the new oxygen sensor by hand to prevent the risk of cross threading. Tighten the sensor with the oxygen sensor socket and ratchet. Torque the sensor to 31 foot-pounds with your torque wrench. Press the electrical connection together.
Raise the truck slightly, then remove the jack stands. Lower your truck to the ground.
