ok first time writer here. i have a 2004 f150 with 5.4L, i am getting a #4 cylinder misfire detected, i only have problems around 2000 rpms, and always when im driving down the freeway and i start to pick up speed slowly, if i throddle down hard it will clean up and runs good, i have changed all the spark plugs and swapped the syliniod pack with # 2 and the problem stayed on cyl 4, my next guess was dirty fuel injector, ive run 3 bottle of cleaner with 3 tanks of gass and still not any better, need ideas, should i pull out the fuel injector or does it sound electrical, plz help, sincerly starving college student.

 

Welcome to FTE CLutchf250! I assume you mean that you swapped the COP from cylinder 2 to cylinder 4 and the problem stayed at #4. Injectors can be switched around too. Just be careful of the O rings that seal the injectors into place. Good luck!

 

ok so i swapped the fuel injectors, too easy! and it still shakes, but i cant get it to trip the code, so i dont know if the problem followed the fuel injector or if it stayed at the #4 cylinder, guess i just keep driving till i get the code or buy a new fuel injector huh?

 

You may still have COP problems. I am having a similar problem with my truck. Changing the plugs helped it a lot but didn't fix it completely. I bought all new COPs for it but haven't put them in yet as I was waiting for better weather. It's getting around to time to do them now. Good luck!