DS Action Replay with GBA Games in DS Slot-2? No—Slot-1 AR Can't Patch GBA Mode

No. A Nintendo DS Action Replay (Slot-1 card) only patches DS-mode software. It cannot intercept Game Boy Advance code running in Slot-2 because:

• GBA mode disables DS hardware (ARM7 only, different memory map).
• Slot-1 is electrically inactive during GBA execution.

To Cheat in GBA Games on DS

• Use a Slot-2 (GBA) Action Replay / GameShark / CodeBreaker cartridge inserted in the bottom slot.
• Or flash a GBA flashcart (EZ-Flash Omega, EverDrive GBA) with cheat database.

DS Action Replay is useless for GBA titles.