If you can get your heep, er, i mean Jeep (lol) to my place, i've got an OBD II diagnostic tool.  It reads all paramiters real time, can look at stored codes, etc, etc.  I can even load the software on a laptop and watch/record a drive to find those intermitant faults.  I'm working from home all week (well, off on Fri), so PM me if interested