I am looking at buying a tuner. I just want it to read codes for now, no new tunes. What 's important is I want to save my original tune I have on the car now. I upgraded to a Roush Phase I charger last year and I would like to save that tune just in case something goes happens in the future. Does the tuner save the original tune when you first connect the device? I was thinking of buying a used tuner that is unlocked/unmarried or should I just buy a new one? Any help would be appreciated. Mitch