Changing the oxygen sensors on your 1997 Ford Taurus will improve the fuel mileage, idle quality and drivability of your car. The oxygen sensor or O2 sensor is responsible for reading the percentage of oxygen in the exhaust emissions of your car. The sensor then transmits that information back to the vehicle's computers in the form of a voltage value. The computer uses this information to alter the fuel injectors pulse width and alter the air/fuel mix in the engine. A malfunctioning O2 sensor will cause the engine to run rich, using more fuel and causing it to run rough.
Raise the front of the car with a jack. Position a set of jack stands under the frame to support the car while you are working under it.
Locate the four O2 sensors in the exhaust system. There are two in front of the catalytic converters and two behind the catalytic converters.
Select the O2 sensor you need to change. A scan tool can be used to identify which one is faulty and most auto parts stores will scan your computer free of charge. Locate the wiring harness connector for the sensor you are changing and separate the two halves of the plug after releasing the locking tab on the connector.
Remove the O2 sensor from the exhaust pipe with an O2 sensor socket and a ratchet. Turn the sensor counterclockwise to loosen it, then pull it out of the exhaust pipe.
Insert the new sensor into the exhaust pipe and turn it clockwise to tighten it. Torque the O2 sensor to 30 foot-pounds with a torque wrench and O2 sensor socket.
Connect the wiring harness connector from the new O2 sensor to the vehicle's wiring harness connector, making sure that the locking tab on the connector engages. Be sure to route the wires from the sensor so they do not contact the hot exhaust pipes. Repeat the process on any of the other sensors that need changing.
Support the car with the jack and remove the jack stands from under the car. Lower the car to the ground and test run the engine to verify that the repair was successful.
