02 7.3l powerstroke won't go over 69 mph
 

I'm new to diesel trucks. This is my first. I was driving down the high way and i noticed it wouldn't go over 69 mph. No engine lights are on. Truck starts and runs fine. And the rpms are just less of 2k while driving around 65-69 mph. When I push the petal to the floor seems like the engine loses power. Called the ford dealership and they told me it might be a throttle pedal sensor. Any other ideas? Thank you for the help.