I have continued issues with misfires on #2& #3 cylinders on a '05 expedition 5.4; this really seems a common prob with this model but I'm ready to shot it and put it out of my misery....I hav replace the coils 3times, and injectors twice and also the plugs. Am I missing something? problem persists

 

You might do a compression check to see if the valves or rings might be the issue. Did you change out the coil boots at the same time you replaced the coils paks and did you use plenty of dielectric grease around the boots to ensure you aren't allowing spark to work it's way to ground along the spark plug channel?
Any codes prompted?