2001 7.3L looses power when warms up

[jonurmford]

I have a 2001 7.3L in an F-250. Been runnung great for 330,000 miles. Last week it started chugging when driving at highway speed. Felt like a dirty fuel filter that had happened several times in the past. Then, changing filter fixed the problem. This time new filter didn't solve problem.

It will start easily. When it has been running for at least 20 minutes, it starts to loose power (I also noticed that I go through fuel a lot faster also). It would never stall or shut off, just get slower and slower. I pulled over and turned it off and thought about calling for a tow truck. After sitting for about five minutes, I started it up and it ran like normal. I drove the 12 miles home.
One hour later I needed to take a 20 mile trip to pick up the kids from school. On the way home it started to chugg again.
The transmission seems to be shifting at normal times according to the power supplied by the engine.

I have an Actron CP9135 scanner and it shows no codes or problems even when the chugging problem is present. Is this the right scanner to use in this vehicle?

Been reading some other threads and looking at a possible turbo problem. Removed the intake tube and found the turbo fan would spin smoothly.

All help would be appreciated. This is both my work and personal vehicle so I need to get it fixed ASAP. Last time I had a sensor problem (about 5 years ago) it cost $580 in labor to diagnose and change a $28 part. Would like to not have to do that again. Still shooting for 1,000,000 miles on this truck.

Thank you