I have a 1997 3500 4x4 with a automatic , missing the cat and muffler. Two weeks ago I had the kdp jigged. I had the stock fuel plate moved forward and the star wheel turned up meaning more smoke. I noticed three days ago I do not have the power I use to in the rpm range of around 2500 and the truck does not want to go over 70 miles per hour. I did by some fuel from a station that I have never used before. any suggestions where to start maybe change fuel filter? any help would be greatly appreciated