If you change the ignition key can you still use your old key for the door locks?

 

Think logically. There are mote than one option when you talk about keys.
Physical key has the groove to match with tumblers in the cylinder. A lock smith can make the tumbler match a key.

Electronics and mobilizer and ECU go together. If I was to get a new ecu and its master key, I would buy a binder with all cylinders.

Technically you can have a different key for ignition and door lock. Just be aware that the slug in the old key next to the new ignition key can confuse the ECU.

There are folks who only rely on remote operating the door lock and dont carry door keys ... I think this set up is unsafe as RX locks out remote if it finds frequency (but missing RF code) form another remote.

Salim