Your 1993 Chevy Corsica uses an oxygen sensor to adjust the air/fuel ratio to optimize the engine operating conditions at any given moment. Thus, driving with a worn-out or failed sensor may decrease your fuel economy up to 15 percent and affect your Corsica's engine performance. The oxygen sensor in your Corsica is very accessible, though, so you can install a new unit without the need to remove other engine parts if it's time for a new sensor. Once you have the sensor required for your particular Corsica model, you can install it in minutes.
Idle the engine for about 20 minutes to warm it up. This will help you ease the threads off the exhaust manifold.
Open the hood and remove the exhaust manifold shield if your particular model comes equipped with it. Use a ratchet, ratchet extension and socket.
Disconnect the negative (black) battery cable from the battery with a wrench. Secure it so it can't slip back into contact with the battery post.
Locate the oxygen sensor. It's mounted on the exhaust manifold close to the exhaust pipe that connects to the manifold. The sensor is a small metal cylinder, about the size of a spark plug, with electrical wires attached to it.
Unplug the sensor electrical connector.
Unfasten the oxygen sensor from the exhaust manifold with a ratchet and oxygen-sensor socket. If necessary, use penetrating lubricant to help you loosen the sensor, says Jimmy Nylund in the Auto Media website.
Apply a thin coat of electrically conductive anti-seize compound to the new sensor's threads if your new sensor comes without this coating already applied.
Install the new sensor finger-tight and tighten the sensor to 30 foot-pounds (40 Nm) with a torque wrench and the oxygen-sensor socket.
Plug the sensor electrical connector.
Replace the exhaust manifold shield if your Corsica model is equipped with it. Use the ratchet, ratchet extension and socket.
Reconnect the negative (black) battery cable to the battery post with the wrench.
