O2 Sensor Origin...

[geodiggr]

Hi all,

Going through the new truck still. Guesstimated a problem with the O2 sensor (Check Engine Soon light would come on as truck warmed up and it seemed rich), bought the new one and went to put it in this evening...well, found the one on the exhaust, started tracing back to the plug...and the darn thing is cut/broke. I'm assuming when there was transmission work done by the previous owner it happened. Anyway, I'd like to know the origin (or the other end) where it plugs into whatever it plugs into so I can try and trace it and find the break. Obviously I'm not seeing right now, nor the plug. My guess is it stuck in the transmission house or lost forever...

Any help would be appreciated.

Thanks,
Rick

PS - I don't have any of the manuals or wiring diagrams yet...working on that now.

[2000CAYukon]

Need to know what year and engine.

//2000CAYukon

[geodiggr]

Dagnabbit...

One kid was crying, one was whining, and the dog was whining, needless to say I had an attention deficit! Alas, the poor spelling on my original post.

Anyway, GMC, 1991, V1500, 350, 4x4, Automatic...

Sorry for my lapse earlier.

Thanks,
Rick

[2000CAYukon]

Well then, I may be able to help you. I have a 90 K1500 with a 350 Auto. I have a full set of manuals but not with me at the moment (I am still at work).

The 02 Sensor (just went out to take a look) is connected to a purple wire and goes into a bundle of wires about 1 inch thick. This bundle goes under the steering shaft in one direction and then behind the motor in the other. You should be able to look inside it for the purple wire.

I can look up where the purple wire goes when I get home (after the kids go to bed) and post if that helps.

I am surprized that your check engine light did not come on with the 02 disconnected.

//2000CAYukon

[2000CAYukon]

Purple wire goes all the way to the ECM.

//2000CAYukon