You said:
The problem is I have this funky smell coming from the exhaust or jeep and I find the engine missing at idle. The smell is bad enough for my apartment manager to ask me to use a different entry into the complex!

Ok the problem IS the CAT! Get the correct one and the smell will stop.
Everything else you have said makes me believe the engine is running up to specs.
The plug description is very good.
You need a cat that will handle the new stuff.
Big JIm