I have a 1985 gl 4x4 D/R EA82 hitachi carb wagon that I'm working on. Cat has an O2 sensor in place but the orange wire and black connector are not connected to anything. Car has no ECU under the steering column. I'm thinkin that maybe the exhaust is not original? IF I have no ecu, were should the o2 sensor connect. Thanks for any help.

I had the same thing on my 86..if it has a carb, then there is no place to hook up the O2 sensor..for what ever reason, sounds like this cat/y-pipe was taken off another car with a FI set -up

Thats what I'm hoping.

Unless it's a CA model, the Y-pipe was probably taken from a later model car. Some carbed subes had an ECM that operated some duty solenoids in the carb, but I have yet to see or hear of a car like yours that has one.