How to Replace the Oxygen Sensor on a 2001 Saturn SL

There are two oxygen sensors integrated into the exhaust system of the 2001 Saturn SL. The sensors help the 1.9-liter four-cylinder engine generate an ideal fuel-to-air ratio for optimum emissions. One sensor is located near the manifold and monitors this mixture. If the mixture becomes compromised (too much air makes the mix too lean; too much fuel makes the mix too rich), the sensor transmits a