Studdering when kicking down a gear

[Im Blown]

Studdering when kicking down a gear. Please Help!

I noticed my truck isn't wanting to downshift into the proper gear when i transition from cruising to hauling a$$. It tries to downshift then acts as if it can't make up it's mind if it wants to grab the lower gear or stay in the cruising gear upon WOT. Anyone know what might be causing this? I have an Amazon custom tuned Predator and I'm running all stock tranny.
BTW if I'm running 60mph and punch it with OD on, it'll studder. However. if I have OD off, it'll downshift beautifully and go.
Thanks and Merry Christmas,
-Joshua

 

[KYLightning02]

mine was doing the same thing a couple of weeks ago and got it checked out and i had 3 coil packs down and 2 spark plugs blown so thats what i would check first but i am no expert on this

 

[Im Blown]

I tend to doubt that it is a spark problem...It'll run like a champ from a dig, seems to me to be a tune issue? Like I said it just has a hard time making up it's mind if I do kick it down from OD to second.
-Joshua

 

[Im Blown]

bump