Customer owned a 2014 ford f150 5L 4x4 with 202K and they are having a problem with the engine first they thought it was the plug and changed it, the problem was still there #4 cylinder and then swapped coil plugs i had used ones still and reset code.and less than 24hrs it came back as misfire again, then they changed all 8 plugs and coils anything related to ignition they told me #8 was doing the same thing but had the dealership fix it so i am waiting to hear back on what they fixed. If any idea please let me know if anyone else had this problem but still problem existing, they are getting this from a neighbor telling them what to change but I'm looking more in depth on this for them. So they left the truck with me I entered the truck VIN searching code still says p0304 but all the parts are brand new