I want to move from EFI to HP Tuners. The last person tuned the car with EFI and I've had little problems since. I want to go back to HP, can that be done easily?
If you have the HP Tuners software & hardware, you're ready to go.
I would suggest reading your current program first. Then visit your tuner and have him revert back to the stock program. Then read it again with HP Tuners. That way you have your stock & modified programs to work with.