Quick question I have a tune already on my car if I order a new hand held can I clear the old tune off or is that not possible because I had the sct x3 but it was stolen and I’m about to order the x4 for new upgrades so I was wondering could I do that[/QUOTE
You cannot "read" a tune from the car with SCT. You can't even pull a tune off the SCT device. (only delete it from the device)
You need that tune you have on your car emailed to you from the engine tuner that created it/tuned your car.
As for going to a new tuner without having the car returned to stock should be possible. I was able to get my car up and running without having my new pcm PMI'd with IDS.
You won't know till you try your new device. Worst case, you will need to have it flashed back to stock with IDS, but I don't think that will be needed.