Hey Guys, I have a 2004 F350 with the early 03 motor. It Has an SCT Livewire Tuner, ARP headstuds, Egr delete,new FICM, 3 Injectors, and 5in exhaust. When i bought the truck, i bought the tuner and exhuast. The tuner has 5 settings, Tow/Haul, 50hp, 65 hp, 100 hp, and 125 hp. Ever since i owned the truck, it seems to have a top end miss around 2600, but only when you put the 100 and 125hp tune. Would this be a tuner issue or is it and internal issue?

 

It doesn't soud like a tuner issue
Is your injectors stock?
I'm thinking the injectors can't handle the 100/125hp setting when your close to your top rpm.
Just a guess,hope it helps.