2001 5.4 screw, 2WD - tanny rebuilt 2K ago.

New issue - it seems to shift fine getting up to speed - the problem/issue is - when running at highway speed, when I let off the gas to exit or slow down it lugs or releases - no change in RPM - it feels like it does when the TC locks in OD. U joints are fine - this is new, and very noticable.

I purchased a Superchips Flashpaq - which I will be returning. I am an old man, and since I don't go WOT or tow, it really won't do much for me. The guys at SC indicated that gains wouldn't be noticable less you really get after it - when you drive with light to moderate acceleration it runs basically stock.

It's never done that lugging before the rebuild or until now - let off the gas and it would coast until it need to downshift based on speed or need. I am wondering of the Tuner jacked something up?

I wouldn't rule out the possibility that what it's doing now is normal - that's what I am hoping you guys will help me understand.

Thanks in advance,
Brad