mustang missing on 2 cylinders?

[blakeley]

ok so i have a 2000 mustang gt it has the stock intake on it the only thing after market is it has cold air intake but i was driving it in the rain one day and stomped on it and it started running like crap i took it had it diagnosed and it said 5 and 7 cylinders were missing it was about a week later and then cylinder 4 went out and i replaced all of the spark pluggs and i replaced the 3 coils on the cylinders that were miss firing the car ran good for just a short amount of time and started acting up again i had it diagnosed again and it says that cylinders 5 and 7 are missing once again got any ideas of what it is?