I hooked a fuel pressure gauge up today and had a pretty constant 49psi even while it was doing its thing, so I'm ruling out fuel, I noticed today while driving in the city the exhaust even sounds weird, kinda like it would if it was restricted, time to cut the cat off and see what the heck is going on!

 

I just thought of something, is the mileage that is shown in the display the mileage of the truck or is it the mileage in the computer, because this ECU is not original?

 

It was restricted exhaust, the cat was screwed, now it runs awesome!

 

Glad you got it.