I had my 2014 JGC reflashed May 31. Since then I have noticed a slight decrease in performance, starting from a complete stop. The most change has been in getting poorer mileage. In town has decreased from 22-23 to 17. Highway has dropped from 29-31 to 24. I also had to return to the dealer to get my check engine light reset a few days after the reflash. Has anyone else suffered this mileage drop?