My truck runs great if I keep my foot out of it. But recently its started to develop a problem. It pulls real hard in first gear (all rpms). Shifts to second pulls great(all rpms). But once it shifts into 3rd it just falls on its face. It wont keep pulling it just feels like its draggin a lead weight. Once it shifts into 4th then it takes off again. Im not sure where to go. Or what to look for. I am running a bullydog, and this problem is only evident in performance or crazy larry. Any advice would be great. If this is in the wrong area it can be moved. But since Im not sure what the problem was I posted here. Thanks

When was the last time you changed the fuel filter?
Easy, cheap place to start.

I will change it tomorrow. Its been about 8000 miles all across the country.

When was the last time you changed the fuel filter?
Easy, cheap place to start.

X2 :agreed:

if it stil does it after the filter change, I will bet you 5 bucks you are running the fuel rails dry if it only does it in the "HOT" tunes. Time for a lit pump. I run mine dry in the 06 in the hot Edge (level 6) al the time.
Are you getting in codes? It may or may mot set a light? My 03 is all stock for now but it will lose over all power when the filter needs changed.