The System Menu (4.3 is the system menu version, not the firmware version) has zero relevance when a game is being run, as it is not being run at that time. What is being run is IOS (think of IOS as being somewhat like the "drivers" on your computer; they let software communicate with the hardware).
But as for Error 002, which probably isn't related to IOS either: assuming you are loading the game via Gecko OS (if you aren't, you should begin doing so when you want cheat codes), there should be an option to bypass error 002 somewhere in the app's options. I'm not sure exactly where, but have a look about in the settings and see what you can find.