06' screw, 5.4L 116K mi
The truck looses power at highway speeds to the point that I need to pull off of the road. When this happens the check engine light is on and the truck is still running but will not accelerate, is it possible the computer is going into limp mode and if so what would cause this?

 

There are many dozens of things that can cause what you are describing. The powertrain computer is warning you that there is a problem (check engine light) and your next step is to connect a scan tool to the computer to find out what it is that the computer has detected.