O2 Sensor - disconnect?

[Pinger]

Prepping for a pending exhaust change and the O2 sensor in the (so called) resonator pipe will have to come out. By the look of it removal is only possible with the resonator removed but I can't see where to disconnect the wiring. O2 sensors I've dealt with previously had a 6'' pigtail but the truck one seems not to. How do I disconnect it?
1999 C2500 5.7 Suburban.

 

[Schurkey]

Follow the harness away from the O2 sensor. There's a connector in there somewhere, probably within 0.3 meters of the sensor.

I've seen sensors that between the location and the rust, the pipe it's in had to be removed to get the sensor out.

Which, if you're replacing the pipe anyway, just means that you've saved yourself the labor of taking the old sensor out. Scrap it along with the pipe it's in.

But, yeah, you've still got to connect the new sensor to the vehicle harness. When you have the new sensor in-hand, you'll know how far back to look for the connector.

 

[Pinger]

I had a look at the sensors on Rock Auto and they have pigtails - just much longer than I've encountered before. Follow that wire....

Old one will go back in. It's a downstream one so doesn't influence fuelling.

 

[1998_K1500_Sub]

Old one will go back in. It's a downstream one so doesn't influence fuelling.

It may someday set a code and light the SES, as one of mine has.
I guess you can wait until / if that happens

I've replaced all four on the Suburban.

 

[Schurkey]

Does the scan tool show appropriate voltage fluctuation/cross-counts?

NOW is the time to access/replace the thing if there's any question as to it's senility.

 

[Pinger]

The existing one appears to be fine. The suggestions to replace it aren't bad - just overlook that it'd be ten days shipping to UK and I'm a bit tight for time.

 

[HotWheelsBurban]

It seems like when I replaced the rear O2 sensor the first time on my Burb, that the original wire was shorter than the replacement one. There's a collar with a push pin on it(similar to the Christmas tree pins on the door panels) that goes into a hole in the box that partially covers the sensor in the exhaust pipe. This can be kinda tricky to get loose from what I remember (this was 5 or 6 years ago, done a lot to both trucks since then!)
If you could get a picture or two of what you're dealing with, I might be able to give you some ideas on how to proceed....

 

[Pinger]

It seems like when I replaced the rear O2 sensor the first time on my Burb, that the original wire was shorter than the replacement one. There's a collar with a push pin on it(similar to the Christmas tree pins on the door panels) that goes into a hole in the box that partially covers the sensor in the exhaust pipe. This can be kinda tricky to get loose from what I remember (this was 5 or 6 years ago, done a lot to both trucks since then!)
If you could get a picture or two of what you're dealing with, I might be able to give you some ideas on how to proceed....

It looks like the usual O2 sensor with wires integral and a connector at the end of them - just haven't located the connector yet!
It's next week's job. This week's is replacing the 1/4'' brake pipe in three sections from ABS unit to rear flexible hose. Would be going better if I hadn't ham-fistedly broke my pipe flaring tool. The joys of GMT 400dom.