Hey everyone i've got a problem! when i go to give my 2.7t gas it misfires and it throws out a code p0304 a misfire on cylinder #4. now i replaced the coil pack and cleaned up the spark plug and it was good for a week and now its doing it again! so im trying to figure out if its the spark plugs i have? they are some new crap E3 (brand) spark plugs with diamondfire technology. now they are supposed to be good for 100,000 miles and i've had them in for about 5,000 lol.
I am going to swap them out this week and was wondering what is the best spark plug for this motor (2.7t)?

 

I had the same problem a week ago, replaced the plugs and it still happened. Moved coilpack 4 to 5 and it followed it. Try switching it with a different one. Possibly your new coil pack is bad or its not the right part number.

 

could also be coil amplifier (think they are on top of air box?)
But first confirm it is not your coil pack as said above, usually is the problem on our cars. Just buy a few and keep them in the trunk unless you ahve a warranty that covers replacement. Other will most likely go soon