The following are known Action Replay Codes for Sonic Adventure 2 on SEGA Dreamcast.
Master Code – Must Be On
DBD307409C684CF8
Master Code – Must Be On
65A0EE4D9C684CF8
Stop Time
E2071FD000000009
Master Code – Must Be On
DBD307409C684CF8
Master Code – Must Be On
65A0EE4D9C684CF8
Stop Time
E2071FD000000009