I just got a 2017 SCREW with 31K miles about a week ago. It had all the options I wanted and looks brand new. The previous owner added several options that I was happy with - powered bed cover, Magnaflow D exhaust, Whipple Cold Air Intake, tinted windows, maybe more. I introduced myself in the new members section with some other details. When I got the truck I noticed that the shifting was very harsh and abrupt at times. It sometimes seemed hesitant as well. The truck was almost undriveable in Sport mode due to the hard shifting. I also noticed from the carfax that there was an outstanding recall on the seat belt. I did some research here and found there was a TSB for the shifting. First cleared the adaptive tables and it got better but not where it should be. I called the dealer and made an appointment. They were very cooperative and did the recall and applied TSB 18-2079. This fixed the shifting but also brought back the auto start/stop function. I was guessing the previous owner had either done a tune or turned that off with forscan so I was kinda expecting that. Last night while driving (next day after service) I got a check engine light. Pulled the code - P0420. Now I'm wondering if there is a problem with the cat or O2 sensors or is this a result of the dealer reprogramming the ECM and the Magnaflow exhaust and Whipple CAI. ANy thoughts or suggestions are welcomed. I cleared the code and am waiting to see if it comes back but wondered should I be checking something or looking for a tuner.... Anyway, the shifting is much better. I turned off auto stop/start and a couple of other things (Double honk, numbers over temp) with Forscan. Overall really happy with this Raptor if I can get rid of the code. Thanks in advance for any advice.