My 96 9000 aero has the engine check light on. I checked the code, it called out
a P0133 O2 sensor located at Bank 1 Sensor 1. Where is Bank 1 Sensor 1 located on the car ? I see part stores sell universal O2 sensor, can they be used. Any help is appreciated.

If my memory serves me correctly, bank one sensor 1 is the 02 sensor AFTER the cat. This is if you have a 4 cyl version. This sensor does not really do anything as far as altering the A/F ratio, but you will fail emissions because of it. It job is to tell the ECU if the CAT is working properly.
Tom
Also, universal Bosh 4 wire O2 sensors will work.