I was thinkn about getting a tuner but i dont understand them fully. Does the diablo tuner come pre-tuned or do i have to figure that out myself if someone could give some info on the diablo tuner i would appreciate that.....

 

The diablo will come with at least one tune, usually just a 93 octane performance tune. You do have the option of adjusting the tune if you so wish. I wouldn't recommend messing with it too much if you don't know what your doing. However making changes for gears and stuff like that is pretty easy.