I have a 2004 F-250 with a 6.0 and am having a serious issue. The truck has about 240,000 miles and has been great until now. About a week ago the truck was running great and had plenty of power. I decided to wash it with my pressure washer (did not spray under the hood, however I did spray in the front wheel wells and underneath the truck). About 5 minutes after washing the truck, I took it out for a drive and noticed when I really got on the accelerator the truck would not want to try harder and motor got very quiet. Really all you could hear was the turbo whistling. Over this past week the problem has gradually gotten worse... a few days ago I had to feather the pedal in order to go up hills. If I gave it more than about 1/4 inch of accelerator, the motor once again would get quiet and the truck would start to slow down and would not want to work. However, if I let up and only gave it a small amount of accelerator, the motor would sound normal again and it would pull up the hill. Today, I can do nothing more than idle back and forth in the driveway because the motor gets quiet and the turbo winds up if you give it even the slightest amount of accelerator. I have no idea if it's a coincidence that this happened after washing the truck, or if maybe there was a sensor that was rotted and about to die and I finished the job with the pressure washer. I already replaced the egr valve and have been running tons of Howes diesel conditioner and anti gel through it. The injectors were replaced about 50,000 miles ago so I'd hate to think it was them. The truck doesn't smoke at all either, so I'm out of ideas. I really appreciate all of the help I can get, thanks so much!

P.S. I know the fuel gauge reads empty...it's broken. It positively has fuel!