Some secret codes not working after installing CyanogenMod I installed CyanogenMod on my Galaxy SIII I9300, There was a secret code that shows MAC address of the device: *#232338# that was working when original stock ROM was on my device. But it does not works now. Is the secret code list differs between original stock ROM and CyanogenMod? If yes, where I could find new secret code list?
Some "secret" codes are provided via hidden apps that the carrier and/or the device manufacturer installs in the phone's firmware. When you switch to a custom ROM such as Cyanogenmod, those apps are no longer present.

Nevertheless, for just about anything you might have wanted a "secret" code for, there is some way to get that information already, either through an existing menu item or a free app you can find on the Play Store.