I have the 2013 Dodge Dart rallye with the 1.4l turbo in it. I get regular oil changes and put 89 octane in. If I could afford the 91 I would get it but I live in California so gas is expensive and can’t afford it. Anyways, before I moved to Cali I put regular 87 gas in and it drove great. I got to California and started to slowly put 89 in and everything was fine. I woke up one morning a few months later and the car was misfiring really bad on the cold start and when I drove it, it would misfire under load. Switched some coil packs around and found out it was the coil packs so I replaced those as well as the spark plugs. It drove great for a few days. A few days later and the same thing, it’s misfiring. Same cylinders. Again switched coil packs and the misfire moved with the coil pack. This has happened many times in the last few months and it always boils down to the coil packs. Has anyone else had this issue? Could it be that the wire harness for the coil packs is going out and making the coil packs go bad? Any information would be appreciated! Thank you!