The Chrysler oxygen sensor is one of the many types of components that help today's computer aided engines to run more efficiently. There is only one oxygen sensor on a Chrysler so when it fails it must be replaced immediately or your engines performance and mileage will be adversely affected. The Chrysler oxygen sensor is located on either the exhaust manifold or exhaust pipe and can be accessed from under the hood. As with all sensors on your engine, when it fails to function properly the check engine light will appear in your dash. A technician or a Chrysler owner with a service manual that includes the codes can determine just what the failure is and if it is your oxygen sensor that needs replacing. The purpose of the oxygen sensor is to make a direct comparison of the oxygen level in the atmosphere around your vehicle to what is present in your exhaust gases. This information is one of the calculations done by your onboard computer to determine the correct air to fuel mixture each cylinder should receive. When faulty, this sensor will be sending inaccurate information and your engine could be running rich or lean, both of which will hurt its performance and mileage. The replacing of the oxygen sensor is a task a Chrysler owner can complete themselves. The engine should first be cool and the battery disconnected. This will not only make it safe to work on this and other electrical parts but also clear the codes in the computer. The wire to the sensor should be disconnected. Because there is a wire on the sensor a socket cannot be used to remove it, only a wrench. Tighten the new one in place and reconnect the wire then the task is complete.