Have a question for someone........ have a 2005 F250 with a 6.0. When driving at a normal speed of 55 mph turbo will boost from 5 to 15 or 20 and then go back down. Not putting my foot to the pedal or anything. It is a constant up and down. You can watch the boost gauge and you can here the turbo as well. What would be causing the turbo to be boosting when it is not supposed to? At idle it does not have this problem also when you put the pedal to it everything seems to work right.........
Replaced Map sensor but that was not the problem....... what should I check next?

 

Moved to the 6.0L Powerstroke Diesel forum.

 

Have you checked the codes yet? If not, do that next. That's gonna be the best way to move forward. If the turbo's kicking out, there's gonna be a stored code or two.

A bad EBP sensor can cause turbo issues, as well as needing to have the turbo reconditioned.