Ditto...after hearing about the putz hacking off a good cat with a sawz-all as a diagnostic test (where did that idiot work??) you need to take a peek and see that the O2 sensor and it'* wiring are plugged in and not hacked through.

Meanwhile, now that the car is more or less running, it'* time to buy a real scan tool and learn how to use it on your car to track down anything else that is out of whack.

the sensor is plugged in and no loose wires, but the Code 13 is intermittent, and seems to change when I comes on and off, and I cant nail down a pattern, but what I'm worried about is that when the nut job went whacko on my exhaust pipe with the sawz-all (reciprocating saw) that the severe vibration and back and forth tearing motion somehow managed to destroy the O2 sensor, making me need a new one. So if this is the case, how much should an o2 sensor cost, and how hard are they to change. Thanx!

Cost, take a look at the prices on the auto parts websites for the chains near you.

The process of changing one isn't that bad. There'* a specialty socket (with a slot for the wiring to pass through) that will make removing the O2 sensor a much easier task. Soak the threads with PB blaster, than take the unscrew the sensor.

You don't even need the socket. A crescent wrench works fine.

and it only cost $35 to have the cat welded back in, and I made the wacko who sawed it off reimburse me, I only thought it was right since he didn't offer to weld it back on, and only made my car run, and sound like total *#!^. Any who, Im looking for O2 parts, and any suggestions for a real scan tool?

Actron CP9110. There are usually 2 or 3 new ones on ebay for under 100 bucks. Right now there'* only one used unit.

Sometimes...depends on how rusted up it is....if it'* really seized in the bung tight, you'll take the flats right off the sensor with a crescent wrench before it comes loose. Spreading the torque out on all six flats on the sensor is usually the ticket to ensuring it comes out.

Normally, sticking the crescent wrench, box wrench or O2 socket on it after soaking it in PB and giving the handle of the wrench a sharp thwap with a rubber mallet will pop it loose. It will thread right out of the bung without effort or bleeding & busted knuckles.

The best thing to install one is the socket with the slit in the side. It keeps you from mangling the wire. And it is easy to use a torque wrench to know you have it tight enough, but not too tight.
After soaking with PB blaster at least overnight, a pipe wrench with a cheater bar will guarantee something is coming off. You can snap the sensor in half with a pipe wrench, so be careful.
I have heard that it ruins an O2 sensor to run the engine with the exhaust pipe that short. I can't verify that, it'* just something I have heard.

It doesn't. Various chemicals will kill it (like burning off coolant) and oil in the exhaust will foul it up so it doesn't read right. There is a procedure for cleaning it using a torch to burn off any residue on it. (I've never done that though, I just chuck it in the trash and put a new one on.)

Not really applicable here though...it'* showing an intermittent open circuit so it is either damaged internally or there'* a wiring problem between it and the ECM.

well I took a trip this weekend and on the way there ( 150 Miles) I had intermittent SES light, but didnt check the ALCL because I assumed it was still the O2, and it may have been, but on the way back today, No SES and I drove various speeds and RPM the whole 150 miles, could it be that the ECM finally figured the mess that the car was in, out? I disconnected the battery when I changed the Plug wires (Since I was near the alternator) So i know it was relearning the car. Well what ever it is, all is well with the car, and it better by god stay that way for a while, I am not a rich Bonneville owner, LOL!