My 04 sonata with 100,000 mi had a misfire in cylinder 5 code recently. I replaced the plugs and wires and the misfire went away. It drives fine the majority of the time but once in a while the engine will rev between 3000 and 4000 before shifting. I notice it the most when accelerating around 40 mph. Not sure how changing the plugs and wires could affect the transmission shifting. Any help would be appreciated.