Not the same vehicle and I'm not looking to spook you but my commuter Hyundai Accent threw a misfire code. Dealer checked it out, didn't see anything. Happened again. They looked deeper. Next thing I know, my car is torn apart in the shop, I've got a rental and engineers from corporate are being called in. Bad head casting. I got a new head, proceeded to run the car into the ground and when I retired, traded it in on my old TJ. If it clears up, plug looks good, probably water in the fuel.