O2 sensor problems

Is there anyone in here that knows where the O2 sensors wiring is run throughout my car? Both of my rear O2 sensors are reading 0 mV after startup. We're thinking the heater wire is broken somewhere before it splices off and runs to the seperate sensors. I've got to figure out where to look for the wire but I don't know where it runs. :confused:

I know you all probably have cool plans on how to spend your Memorial Day weekend, but I get the privliage of spending part of my long weekend on my back under my car with a flashlight. :banghead:

hmm, i decided to put my 2 cents in just because no one was helping u and i hate to see that... are u sure there is a heater wire? the o2 sensor i heated by the exhaust not a wire... did u ever try replacing the sensors? maybe they are bad? or maybe u have a bad connection? i really wish u luck if u do end up having to chase wires... i've always hated that kinda stuff...

hmm, i decided to put my 2 cents in just because no one was helping u and i hate to see that... are u sure there is a heater wire? the o2 sensor i heated by the exhaust not a wire... did u ever try replacing the sensors? maybe they are bad? or maybe u have a bad connection? i really wish u luck if u do end up having to chase wires... i've always hated that kinda stuff...

The newer OBDII's use a heater wire for quicker closed loop operation (more emissions junk). However, I didn't think the rears (aftercat) were heated?

the wire harnesses should run up the frame from the O2 sensors, up to the PCM on the passenger side of the engine bay.

Ok, I've heard about the O2 sensor after the cat, but I've looked for it and no joy. Does a '95 3.4 'maro have an O2 sensor after cat?
Thanks guys

Take your car to a local LS1 shop, and have the codes removed from the computer for the rear O2's. I needed this with my hi-flow cats. The rears were throwing a code.

I have had my O2's on and off so many times....
The wiring for the driver's side runs up from the O2's towards the motor, then across to the PCM. Never gotten far enough under the car to check out the passenger side wiring. Probably close to the same, just on that side.

Camaro Rookie, you dont have after cat O2 sensors, you have a three way catalytic converter with only a pre cat O2 sensor.

OK, good.
Thanks Iroc.

Thanks for the help you guys...now for the update...I have no f*****g clue. :wtf:

It threw the codes for the heater circuit. I spent the better part of a day going through my car with a test light and a meter, results, everythings fine. The sensors are warming up, the grounds are good, I ohmed the wires from the pcm to the sensors and there doesn't seem to be a break in them, all connections are tight, no wires burned or rubbed.

I'm desparate at this point so I'm clinging to anything, I went through the wiring diagrams and found the same wire that runs from the pcm to the sensors also connects to my skip-shift solenoid. The closest thing to an answer that I have is maybe there is a break in my skip-shift eliminator and that causing havoc through the circuit. I really don't know. I unpugged the eliminator and I'm gonna drive it around for a few weeks to see if starts acting up again.

I will say it again....

Take it to a local LS1 shop, and have them take the rear O2 sensors outta the computer. Mine cost $75.

Oh...I was thinking you meant having the codes cleared. You're talking about actually reprogramming the computer. Now would there be a benefit of doing this opposed to O2 simulators?

And it wasn't the skip-shift. We're hooking it up to the Tech 2 on Friday, if we can't figure it out with that...the cats are going :wave:

It costs the same as the simulators, and it won't ever fail. Simple reflash, and the computer doesn't even know they are there.