06 6.0 seems to be losing power
 

This is my first diesel so I'm really don't even know where to start. I got the truck about 6 months ago. It has 130,000 miles on it and is stock to my knowledge other than cat and muffler delete. I first got the truck it got to where it would start fine when cold but after getting to temp it wouldn't hardly start. I took it in and they said it was a high pressure oil leak. Got it fixed and ran fine. Then power steering pump went out so I replaced it myself. This is my daily driver. Occasionally towing but nothing major. So no more issues until a few days ago I was at about 50mph and started up a hill and floored it and all it did was slowly lose speed. it runs fine at lower speeds, idles fine, ect. But when wanting to pass somebody at highway speeds it's pointless. It will push 20 to 25 lbs boost as normal when wide open. Have no clue where to start. Any help would be greatly appreciated. Keep in mind I'm new to the diesel world. Thanks in advance.

Might be starving for fuel, check the fuel filters and then check the fuel pressure. Could be a bad lift pump. Is there any smoke? White or black? any codes?

No codes as of yet, and no smoke. And I forgot to add that water separater and fuel filters were changed about 6 months ago. The people that had it before me changed them.

I would start with the simple stuff first, I would change the filter again just to be safe and make sure they are the Ford filters and then I would check fuel pressure. It sounds like a bad lift pump.

Ok. I really appreciate it. I'll let yall know what I come up with.

FILTERS FIXED IT GUYS! Thanks for the help