Wanting to see if anyone knows why my truck is misfiring. So I got the 5.4 3v and it sometimes comes up with a P0300 misfiring code. This code only pops up when accelerating at highway speeds. Around 60-75 mph and above 3000 rpm. The body of the truck has 187k miles and the motor has 47k miles. I have already replaces the spark plugs, coil packs, and fuel filter. Would the VCT solenoids be causing this issue? Fuel pump maybe? I am not sure at all what to replace next. Any help would be greatly appreciated!