I checked today to find out hich white wire was my hot on the 3 wire o2 sensor. They read the same ohms. I need to hook it all up tomorrow so help is appreciated. I got the sensor from a 91 zr1. The plug it came with has --- a b and c slots. Maybe a certain slot is the hot and the otheer is ground. IDKK. please help

 

Two wires should be the same color. Those are hot and ground. It doesnt matter which one. One wire goes to a pink and black ignition wire, so it only comes on when the key is on. The other wire goes to a ground on the engine or chassis.

The third wire that is a different color is the signal wire and needs to be plugged into your stock O2 sensor wire.

 

lol i totally searched. I was getting the understanding that one was hot and the other was ground. As in one was only a hot and th other was for only a ground