Why do some codes not work for heartgold in action replay?

Answer 1

Cause some codes are only meant for some games. like the code Walk through walls have different code versions for games. The way things work is that the action replay provides codes for games. if you write a code wrong, the action replay detects the error and tell the game what to do. like you try to get a Pokemon, write the code wrong, and you get a bad egg. So, either the code isn't for Heartgold, or you wrote the code wrong.