Instructions
Inject "Pokemon Emerald" into the Action Replay GBA. Place the cheating device into the GBA cartridge slot of the Game Boy Advance. Turn on Action Replay GBA with the AR switch. Switch on your Game Boy Advance.
Wait for the cheating device to examine and identify "Pokemon Emerald." Highlight the second option with the D-pad. Choose "Select Codes" with the "A" button. Select the button that is marked with a plus sign.
Create a descriptive name for the cheat with the keyboard on the screen. For example, enter "Deoxys Cheat" or "Deoxys Without Ticket." Make sure you didn't make any mistakes and then select "Next" at the bottom of the GBA screen.
Enter the following hexadecimal characters: 25214170 0AB256A2FFA6733C EE552E68 2E7B7A58 D0781742 798A3738 3F94DB5D. Double-check the code to catch any mistakes. Press "Next."
Scroll down to the name of your new cheat with the D-pad. Press "A" to activate the Deoxys cheat. Start playing "Pokemon Emerald" by pressing "Start." Load your "Pokemon Emerald" save file to play with the cheat enabled. Look for Deoxys in the long grass of Hoenn. Throw any Pokeball to catch it.