You'll want an actual tune, not a POS OBD2 port wannabe. HPT gives you the ability to tune. I'd contact Overkill for a tune, or maybe wait a week or 2, since Reptile is "researching" 04+ tunes. Reptile is a member of the site and has fantastic tunes, I have one on my 2000, but he doesn't do 04+'s yet.
What temperature is your transmission running at?