How to Replace the Oxygen Sensor in a Chevy Expressby Jody L. Campbell
The Chevy Express van was introduced in 1996, taking over for the older G-Series versions. Like the G-Series, the Express featured three weight classes and several different engine options. While the location of the oxygen sensors on the exhaust systems is fairly standardized, ensuring you're replacing the correct one may require a little diagnostic time. The Express features V-engines, meaning it employs a right and left exhaust manifold. Each manifold is monitored by an upstream sensor. The converter or converters are also monitored by a downstream sensor.
Put on the safety glasses and start the van up if the engine is cold.
Crawl under the van to locate the correct oxygen sensor or sensors to replace. While the engine is running, spray penetrating lubricant along the threads of the oxygen sensor. Keep spraying on and off and allow the engine to run for a couple minutes to warm up the exhaust system.
Crawl back out and shut the engine off and then return to the oxygen sensor with the remaining tools.
Disconnect the wire harness plug from the oxygen sensor.
Place the wire into the slot on the side of the oxygen sensor socket and then place the socket onto the oxygen sensor. Attach the ratchet to the socket and turn the sensor counterclockwise to unscrew it from the exhaust port.
Insert the new oxygen sensor into the exhaust port and then thread it in by hand as far as it will go.
Tighten the sensor with the socket and ratchet clockwise until it's snug. Do not over-tighten or you'll strip the threads of the new sensor out.
Reconnect the wire harness connection. Remove the tools and old sensor.
- The new sensor will take about 50 to 75 miles of normal operation to recommunicate to the computer in the Express and shut off the check engine light (if applicable).
Items you will need
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