Wow, it's very surprising to hear a story like this. Most of what I've heard is something like this "Yeah, we saw you have aftermarket foglights, so we won't cover your busted differential." Or something ridiculous like that lol.
Currently I have a CEL and Dadeland Jeep told me that it's an evap issue. They claim they can't clear it and it might be something as simple as a loose gas cap. This happened about two months ago, I learned to live with it. It doesn't affect drivability at all. Maybe, I'll stop by Arriago when I'm in the area.