I reverted my car back to stock from supercharged and now I have the P0132 (High Voltage, Bank 1, Sensor 1) which is my primary O2 sensor. I replaced the O2 sensor twice now and the code keeps coming back after a reset.
I took to a shop and they found nothing shorting but found that my ECU was not putting out enough, .3 volts when it should be .8 volts? What would make the ECU fault out like this?

 

I think I might've solved the problem. I noticed my tuner cut one of the wires on the harness and connected the wideband sensor (blue wire on the right), I reconnected the original harness wires and after 3 minutes the light hasn't come back on...weird. It would normally come back on right after 20-30 seconds. All fixed now and passed emissions.

 

Glad you sorted that out. He shouldn't have cut the wire. It would have been cleaner and better if it were de-pinned/re-pinned. It would have also helped if he told you about it

 

What he said