The data the Buick Oxygen Sensor is sending to the onboard computer is the ratio of oxygen in the exhaust gases as it is directly compared to what is present in the atmosphere surrounding the vehicle. This is one point of data that is used in the proper determination for the air to fuel ratio your Buick engine should be using.
The Buick oxygen sensor is located on the exhaust pipe just below the exhaust manifold. It can be seen from under the hood of the vehicle but is easier to access from under the vehicle. This is an electrical component on your Buick and in time will fail. The check engine light will become illuminated on the dashboard when the oxygen sensor fails to send a signal. The effects on your engine will be a slight reduction in fuel efficiency and less power at the disposal of the driver to utilize.
When the oxygen sensor fails and the check engine light is on, a code is stored in the onboard computer. This code can easily be retrieved. There is a different code for each sensor so by knowing the codes as they are listed in the service manual, you will know for sure the failing component is the oxygen sensor.
The replacement of the oxygen sensor, or any sensor on your vehicle should begin with the disconnecting of the battery. Not only will this eliminate any possibility of the technician or owner from being shocked when working on the electrical system of the vehicle, but it will also clear all of the stored codes in the onboard computer. This way the check engine light will go off on your Buick and a false reading will not occur when the vehicle is started up after the repairs are completed.