Pete Lech

No you will not lose the programming of the old remote, as you reset both If reprogramming doesn't work, the old remote is unaffected.

My wife lost her key, and I bought a replacement remote and blank, and had the dealer cut the blank. I then went home and programmed both remotes. See the instructions at http://p-car.com/diy/remote/ Use the '95 instructions, which cover all later 993s - the first year's production used a different system w/o remote locking.