I've got the two 4-wire O2's that came off of my '97 Z28. They are the after-cat ones. Does anyone know how to hook them up? They have 1 purple, 1 tan and 2 brown wires.

 

I don't know what wires go to what but do a search on google, I'm sure there is info somewhere out there.
1 wires are grounded through the body and the lone wire is the signal. 3 wires are also grounded through the body, 1 signal, and 2 for the heater element. 4 wires don't ground through the body, 1 ground for signal, 1 signal, 1 ground for heater, 1 hot from a relay.
Heated sensors are good for headers or downstream of manifolds. I like the heated sensors myself. I have a feeling that they last longer or it might just be my impression. I just think anything that heats up fast, controls temps, and is pretty much self cleaning would last longer than something that isn't.

 

Are you trying to use this on a TBI application?

 

Yea ShiftyCapone, would like to be able to use it on my '91 instead of paying $100 or more.

 

Any more ideas anyone?

 

The purple wire goes to same purple wire going to your single wire sensor. The tan wire goes to chassis ground. One brown wire goes to key on power source and second brown wire goes to chassis ground. Basiaclly purple and tan are related to sensor signal. The two brown wires are for the heater curcuit.