I purchased an OBD Scan tool from www.obdcom.com
I mainly purchased it to look for any trouble codes on my CSRT4 and my wife's Grand Caravan SXT. Works very well. Easy to use. Just connect it to the OBD2 port on the car and the other end of the cable connects to the USB port of any laptop. Turn the key to Run and launch the software. You can also monitor engine performance while driving (have your passenger do this actually
I found no trouble codes or any incomplete diagnostic tests. I was mainly worried that the Stage 1 would throw some type of hidden code during emissions testing. But no codes were shown and everything is fine. And you have the ability to clear any codes if found.