Earlier I had asked a question about where my O2 sensor was located. I have a 95 Teg LS. Thanks for those who got back to me.

I was having a problem with black deposits on my bumper coming from the exhaust. Did a ECL diag and got a code 6, coolant temperature sender sensor. Replaced it and life is good. Did a tune-up and air filter change for good measure.

Originally I thought it might be the O2. I guess the moral is listen to your car first and save some time.