'01 Camaro oxygen sensor problem

Hey everyone I have an interesting problem, and I apoligize for how long this thread is. My check engine light came on, so I went to Autozone and had them scan it (Car is v6 3.8 by the way) . I also scanned my car with my own tool. Both came up with codes P0138 and P0140, which means input voltage is too high and insufficient activity, respectively. And this 02 sensor is in bank 1 sensor #2. The other 2 sensors were operating fine. So after asking some auto part stores, I found that this sensor should be after my cat. convertor. So after jacking the car up, I could not find this sensor. I searched all around the exhaust manifold and there is nothing, nor a hole for the sensor to be screwed into. I bought this car used and it does have an aftermarket muffler/exhaust. And there's a 1-2 ft pipe that is welded in to this shortly after the cat. convertor, because I guess it wasn't the right size for this car. But anyway, that's not the problem, when they did this they apparently decided not to put the sensor back in (this is not the 1st screwed up thing that I've had to fix because the previous owner did some crooked fixes). I did see 4 wires kinda near this area, which I think the other side of the o2 sensor would be plugged into. These wires are attached to some sort of sensor type thing, which no one seems to know what is. One of its colors is different than what it's attached to and its just kind of hanging there wrapped around something. The sensor I think says Rodon? on it and has a small, red indicater light on it (I have described this part to auto stores and they have no clue). So I guess the prev. owner just attached this to make it look fine?

I would like to know if anyone knows what color the wires should be on this sensor. I think the colors of the wires were red, black,blue,purple. And the mystery sensor was the same except white instead of purple. I would like someone to verify that these four wires are indeed the ones that should go into my o2 sensor by telling me what colors they should be. Also, if they are then is it possible for me to drill/poke a hole into the exhaust right after the cat. convertor and screw the sensor in and attach it to these wires.

I would appreciate any help as this car has been a headache and a major mistake on myself for purchasing it from this crook.

Thanks for reading,
Greg

The diagram I have shows pink, black, gray, and dark blue for the rear O2 sensor. Pink is 12v for the heater, black is ground for the heater. The other two come from the PCM for the sensor. I will look on mitchell tomorrow, I trust those diagrams more. I have heard of people putting in some sort of O2 sensor deletes so they don't have to use a cat.

When i looked under the car last week I thought I saw blue, black, red, white. Maybe the white was actually gray and the red was actually pink. Does anyone have a mitchell account that could verify that?

Thanks!

Instead of replacing the sensor and welding up an O2 bung to the exhaust pipe, I would just tune out the rear O2's. This way, you won't have to worry about it anymore.

What do you mean by tuning the sensor out?
How would I do that? Isn't that going to kill my gas mileage? I'd rather fix it right. Could anyone advise me on how to insert a hole into the exhaust pipe and attach the o2 sensor?

Thanks

You'd have to dirll it out and tap or weld in a bun for the sensor to thread in to.

How far down from the cat converter does it need to be or does it matter?

What's a bun and do you know what size it is?

Thanks for everyone's help! I really appreciate it.

Well, heres the O2 bung that you would need to complete your project.

http://www.slponline.com/view_product.asp?P=30115

But I serious think you are doing this the hard way. Just go to a performance shop and have them tune out the rear O2’s through the PCM. This way, you won’t have to worry about it again.

Or else, like mentioned above, you will have to drill out a spot in your exhaust pipe, weld up the bung and buy another O2 sensor. Just get it tuned out and not worry about it. Most of the modded f-bodies out there with aftermarket exhaust get their O2's tuned out because most don't run cats anyways.