Cadillac Repair: 1992 Eldorado, o2 sensors, fuel consumption

Question
I have 3 questions; first, my check engine light is on.  Is there a way I can read the code before spending the money to have a garage do it?

Second, my exhaust has a very strong/rich odor, and my fuel consumption is terrible.  Are these related?  

Finally, how can I check my O2 sensors to ensure they are performing correctly

Answer
You can check the codes by holding off and warmer on the a.c. panel.
The smell is directly related to fuel consumption, many possibilities, i would point at the spark plugs and air filter first though.
You can pull the o2 sensor out, it is in front of the catalytic converter underneath the car, somewhat towards the engine.