I HAVE A 2007 F250 AND WHEN IT SITS FOR A FEW HRS IT MISFIRES AT START UP THEN GOES AWAY NOTICED WHEN PULLING A TRAILER THE OTHER DAY WHEN IT DOWNSHIFTS AND RPM'S GO AROUND 4000 SES LIGHT FLASHES THE ONLY CODE IN THERE AT THIS TIME IS P0316 BUT HAS SHOWN MISFIRE ON #7 IN THE PAST I HAVE CHANGED SPARK PLUG, COIL & BOOT AND SWAPPED INJECTOR TO ANOTHER CYLINDER, PREVIOUS OWNER SAID THAT THEY HAD JUST REPLACED ALL INJECTORS THANK YOU FOR ANY HELP, MIKE