Keys Stolen, Key fob overwrite

so the keys to my truck were stolen along with my wallet. I am wanting to replace the key fob, will the new key fob overwrite the old one? or will the old one still work.

If the old one will still work, is there a way to delete all previous key fobs?

I don't want someone to be able to unlock my truck. I plan on replacing the outside locks as well.

 

if you haven't dealt with this yet, here is your info.

you can have the immobiliser ecu reprogrammed with a new code. erase all the keys and new ones programmed. make sure you have the outside lock cyl replaced. Toyota sells a re-keying kit.