check engine light came on then went back off when I restarted the engine. its back on again and was diagnosed with a o2 sensor code. now heres the stumper...... sometimes when its started I get a grinding type of noise when putting it in any gear (auto trans) and at the same time lose all electrical function. turn it off and restart it and its fine for awhile. could this be a computer issue or loose conection somewhere?

 

Look at your O2 sensors and the wires that go to them. I've seen a lot of posts about the wires getting torn up and causing problems.

 

thanks, I put it up on my lift where I could see the sensors and they both look good.