Idt the old key Still works. I've heard of you use the old key it can cause problems if it's chipped or something
my old key that i used was not chipped, the original key has the chip. i took the cover off and put one old key inside above the harness and below the ign switch and wire tied it there and it works good. then i had regular keys made and the chip does it's thing. i wanted to get chipped keys but for one they told me the car only will work with 4 keys and i wanted a key on all my rings. so i got regular keys made of which if you like can be hundreds of them and they have no chip. i have done that trick with 4 cars now and they all work good.
only thing is remember to give the mechanic a non chipped key as if you ust a double chip then the alarm sounds off and won't start. ask me how i know?