Re: code: p304 on our lincoln navigator, need help!!!
It's usually a 7mm six point socket or wrench for that coil hold down bolt. If you want to get to that sparkplug I use a SK flexible 3/8" extension in the 8" or 10" lengths. Like Bert said, take a compressor or something and blow the dirt and debris away from the area before you remove the coil pack so it doesn't go down the sparkplug hole. You can swap the #4 coil pack with one of the others and see if the misfire follows the coil pack.
Rock Auto has great prices on coil packs.