Originally Posted by whilightning
you could always add a permorance chip, not sure how the tuner would affect that though. just a thought, hope you find a solution
An actually "performance chip" is junk to use and more of a money grab with no real benefit to the truck.
A performance tuner (diablo sport, bullydog, superchips being the big brands) are the best way to go and actually show proven benefits over just installing a chip.
If you think there is a tune loaded up.. There is the flash option, but I believe you could ask your shop to hook up to your computer and check if it running stock or a modified tune installed. If there is a tune, then the flash would be a good choice.