Had a new one yesterday. Saturday, I had driven about 700 miles. Sunday, I made a few quick trips around the town I was visiting. At the first stop, nothing seemed out of the ordinary, but when I started the Jeep, the check engine light stayed on. I took it to an auto parts store and had them scan it - The code was P1DBB which they said was a "vendor generic code" and that I needed to take it to a Jeep dealer (which was closed naturally). I continued about my business that day and by the evening, the check engine light had turned itself off, so I have no idea what caused it to come on, and I don't know what fixed it. Is the code stored in the memory still where I can take it to a Jeep dealer and have them tell me what caused it to come on? Or is it just gone until it comes back?