I'm always half asleep, lol, I can relate! Too much work, not enough rest.
I probably did not make it clear enough in my first post, that yes, the whole reason I want to get these o2 sensors out, is to diagnose if my cat is clogged. The way the truck is sluggish uphills
(which really upsets everyone behind me) plus the erratic idle it does on occasion, plus the computer diagnostic said so...this all has me believing the cat is clogged. So obviously, my goal is to create the clean airflow into the cat, and see what happens.

My next question: Let's pretend I have the o2 sensor out, do I need to plug the sensor back in, and let it hang freely, for the truck to run? Or, do I do this diagnostic with the sensor unplugged completely? (because feedback to PCM, I don't understand that part completely)

And, either way with the sensor out, (plugged in,and just hanging, or unplugged) how long can I expect the truck to run with the new air flow hole now provided in front of the cat? Would it be drivable long term this way? At all?

 

You don't need the sensor plugged in after you get it out the bung. It's going to throw the code for it of course being unplugged. And don't let it run long. That sensor helps determine the oxygen percentage in the exhaust, witch fluctuates air/fuel ratio. Take it out, see if it starts without it in there. If it does your cats clogged. Don't let it run longer then you can see if it'll start and run. It's not good. AT ALL! by the way it's going to be loud with the hole.

 

Update, as requested.
The guy that picked up the o2 sensor removal tool for me, decided without warning, that I had only one hour to use it. Which was long enough for me to discover I will be needing a GOOD pipe wrench, and a big *** hammer, and a hot exhaust pipe, to break that sensor loose. But other than that, nothing was accomplished there. At least I did get confirmation from this thread, that I was on the correct path to diagnose a clogged cat, and, I do now know how to do that, if I need to.

However, as I suspected, the truck did fire right up with my battery fully charged. So...I am back to square one with trying to figure out the numerous electrical system problems this truck has.
Over the course of this winter, it seems like having to disconnect the battery everytime the truck will be parked....that often times this resets the PCM, and once in awhile, I get lucky enough that the truck will start and actually drive too! It is never predictable, and lucky for me, I do not need to drive it very often.

I am kind of thinking I should test the alternator at this point. I found this video: And, can someone here please confirm for me, that this is correct information???
I do not have a volt meter, but maybe I can find someone willing to come over and help me with this, provided this is the correct way to do that.

I greatly appreciate all of the help you guys have been willing to give here! I really can not thank you all enough. I imagine it can be frustrating trying to help someone with such basic information.

 

Looks pretty good to me. I don't listen to him droning on though.... just watched what he was doing. Anyone else notice that the negative battery cable was surprisingly loose?

 

Agreed, I had to skip past the first 5 minutes about...and then watch the rest at 2x speed to get through that video! LoL
And Thank you for confirming, HeyYou.

 

That's a youtuber thing.. you drone on and on and almost get to the point long enough to drag out a 10ish min video then have all the information at the end.

 

One of the reasons I try and avoid youtube..... they do the same thing with laptop teardowns..... (which I end up having to watch anyway.......)

 

Getting off subject for a minute https://www.ifixit.com/

As for OP's issue, are you the original owner? Any amps or subs in the truck? Did you install the stereo/system if you have one? Are there any aftermarket lights on the truck? AAAAAAAANNNNNDDDD How old is the battery?

 

Interesting. Thanks for the link.

 

If you think you have a drain. You can hook up your battery and put your leads for your tester (volt meter) on the battery terminals and see if your battery holds charge. Or if it declines quick then you have a drain. since you live where it's freezing cold, it's probably your battery draining itself, And not keeping a charge.