Rough running 5.4
 

hey folks ... i have a 97 f250 with a 5.4L .. would not even call it that though .. it is the 250 light duty or heavy half .. what ever you feel like calling it that day ... but i am having problems with it having a rough idle and running even rougher .. i have recently changed the following

plugs
dpfe
egr solenoid
crankshaft sensor
fuel filter
o2 sensors

and each thing i replace the truck continuously gets worse ... and every time i call or go to the parts house they tell me to try something else ... plus i keep getting a check engine code *p0300 random/multiple cylinder misfire* ... but sometimes i check the codes and it will tell me an actual cylinder that is misfiring .... any help here would be greatly appreciated ...

If you have individual coil packs on each cylinder, I would try replacing the boots first, then if that doesn't fix it, buy 1 coil and swap it with each one until the problem goes away, or lessens. (You may have more than 1 coil pack defective) They will not always indicate that they are bad when you test the resistance on them, so drive it after swapping the pack.