My truck skips at 50 mph, similar to sparkplug misfire or water in the fuel. It idles fine and doesn't have a problem until speed reaches 50 mph.

 

Hello, I have a 05 with the same problem. I've had it to the dealer 3 times and he says its the tires, but I drove one like mine with-out the H.O. motor and it did not skip. Mine is 5.3 H.O. auto, 4.10 4x4 and from 50 to scary it does it, makes for long uncomfortable trips.

 

are you running HIGH test with the HO
that makes a diff on my 05
when i had it