U can't
Either you import them from previous games, use an Action Replay or wait for any official Pokemon events.
there is'nt an action replay code
No, you cannot go to johto. There is however a way to migrate johto Pokemon to D/P. When fishing around in the D/P action replay codes, I found a way to make Pokemon say they are migrated from Johto (Instead of Kanto or Hoenn). This may mean that there will be a remake of Gold and Silver.
no you cant unless you have an action replay to catch trainers Pokemon but other then that you cant catch johto starters in the wild
depending on which game only sinnoh and johto games will work
Uh...there isn't one...
trade, using cheat codes with a flashcard or by using action replay
Enter the code: 94000130 FCFF0000 B21C4D28 00000000 B0000004 00000000 10001170 000000FB D2000000 00000000 Then hold L+R for 2 seconds
you either have to trade with a friend or use an action replay code to catch another trainers Pokemon.
The only way is to get a action replay card and use catch trainer's Pokemon when you fight your rival.
I have two answers for you. In normal gameplay no.maybe if you trade form your platinum diamond or your pearl versions.And you may be able to if you have an action replay sold at gamestop walmart toys rus and kmart
After defeating all eight gyms in johto, professor elm gives it to you. the other way is to defeat all eight kanto, and porfessor oak giths you it, or you get code for action replay, [hack the game, action replay]