x-cal 2 an user programming

some changes can be made with the programmer to the tune he put in there , but its best to call him to talk over what you wanna change

If "tim" put the tune on your Xcal (in addition to your car) and "tim" enabled end user adjustments, then you can tweak the one that's in your Xcal and download that into your car. You will wipe out the one that's in your car.

If "tim" put two or three copies of the tune into your Xcal, and "tim" enabled end user adjustments, then you can tweak one of the copies and download that into your car. You'll still have the original version in your Xcal. If you decide you don't like the tweaks you made, you can undo the tweaks and download that to your car. Or download the unedited original.

If "tim" made you an XTR version of the tune, you can tweak that on your PC using Extreme Tune, upload it to your Xcal (wiping out whatever is at the slot you chose), then download it into your car.