Ok I searched and this question is not covered. I replaced my sensor with the universal one from autozone and when I plugged in the wire to the harness I noticed a copper braided ground wire in the harness side that was not hooked up to anything. Where does it go and what happens when it is not hooked up?

 

The shield terminates about six to ten inches from the ECU plug. It ties in with a black, pure black wire. That's the way I remember it. It does nothing for the 02 sensor reading except act as a rf shield. The 02 voltage is miniscule, as in milivolts being PRODUCED by the 02 sensor itself. Small voltgags like that are easily interferred with by outside sources. Like that heater/ac fan over there in the corner.

 

thanks, I thought it looked as though it was never attached to anything.