I agree with
@CodaMan, don't do anything major till you know what the problem is. Don't take apart the motor. I probably wouldn't swap injectors either. Make sure they are working first. Also don't rely on the paper trick. It is not an exact diagnosis.
The next thing I would do is a compression test. If you have a gauge, then it is free and non-obtrusive. It will tell you for sure if there is an engine problem or not.
I am still guessing it is an ignition problem, unless you already had something wrong, and you just pushed it over the edge. Say you had some carbon like I think
@Squatch mentioned earlier. That could definitely come in a high rev situation, although very rare.
I am not saying that the fuel injectors are not your issue, but it seems unlikely that they just died right then. Not to say they didn't, but again highly unlikely.
It sounds like you are busy over Christmas, and I am hoping despite the TJ issues, you are enjoying you holidays, but you have a lot more room for diagnosis before you start taking things apart, and possibly making things worse.
Start with the easy stuff, as you were doing, and don't lose your head.
Look at the grounds all over you Jeep. If you were stuck in the mud, and if any were loose it is possible you have a bad ground? I know that seems like a stretch with so many different grounds, but to me it sounds more likely than an injector just died. Not saying it didn't, just don't think you should start with the injectors in my opinion.
After you get your grounds all cleaned up, I am talking not just the battery, but inspect them all where ever you can find them, if that didn't fix it, go over the ignition again. That is really where I am betting the issue is, but again it is hard to tell without looking at it myself. If you truly have gone over the ignition, and are satisfied that it is good, then I would do a compression test. That should tell you what your next step is.
To break it down. If you check the electrical, and the ignition, and do a compression test, and it is all good, then it may be time to check the fuel, but I would start with a fuel pressure test because the tester is cheap, and it is so easy to do on the TJ.
A simple compression test will tell you if it is internal to the engine, or not. Please at least do that before you start taking things apart.
I am also betting if you had an actual injector issue, you would see more engine codes. I bet the 02 sensors would have a tough time keeping up with a dead injector. That leads me to believe that the ignition problem is so fast that it doesn't disrupt the normal activities of the computer. Like say if it notices a misfire it probably has to happen so many times in a row before it throws the code, and it may be intermittent. Like becomes more pronounced at high revs enough for the computer to pickup on it? Or the opposite, it clears up at higher revs, and is more pronounced at an idle?
Driving it around a little more might give you more of the story too.
Good luck and keep us posted.
