Cadillac Repair: Oxygen Sensor, rear cylinder head, oxygen sensors

Question
Hello there. I want to replace my oxygen sensor and I'm curious where it is located.  Is there also one or more than one (I've never owned a Cadillac before now)?  I have a 92 Cadillac Sedan DeVille.  Thanks.

Answer
Hi Sean, With your engine you have only 1 sensor and it is located in the exhaust manifold of the rear cylinder head. You will need a special socket that you can get as a loaner tool from Auto Zone because there isn't room to get a wrench in there. It is best to change it when the engine is at room temperature or run the engine for a minuit if it doesn't want to come out. If the engine is too hot when you do get the sensor out sometimes the threads in the manifold will strip out and you will get to practice doing a heli coil installation. BTW it depends on the year and model of engine how many oxygen sensors there are. For example if you had an Eldo of the same year there are 2 for that engine and starting with aproximately '96 there could be at least 4 on a V8 Caddy engine. Hope that explains things. Bill