Quote Originally Posted by Got Milk?
no mods.
Hmmm then I don't really know what it could be.

Staying on boost for a long time would cause a fuel cut. Do you have a boost gauge? If you do, next time you're in 5th, check how much boost you're hitting. Stock you should only be running 12.5psi if I remember correctly. If you're pushing more than that, then you're over boosting thus causing those fuel cuts.