Well good news, I just recently bought a brand new slim PS2. So I will be hacking codes for both Outbreaks and other games too.
For more codes you guys might want to check this
thread.
Here are some ideas I had in mind..
1. A code that switches control between player 1, p2, p3, and p4 (if a 3rd AI is enabled). This will make having other characters in the game more useful instead of relying on the crappy AI. Switch between characters in the game to perform specific tasks etc.
2. Resident Evil 4 camera (coincides with #1, I'll explain why). We found a "spectator mode" code that follows your AI partner (player 2) and resembles the RE4 camera. If I can force the game to switch controls over to player 2 the RE4 camera code will be a reality. I'm doing it this way because so far we haven't found a way to force the spectator mode code on player 1, believe me I've looked everywhere in the dump for it and no luck.
3. Give yourself enemy attributes. This would work well together with friendly fire and the "become a zombie offline" code. Adding a whole new level of enjoyment to the game. Although pretty much pointless, the AI will treat you like an enemy and attack you.
4. It might be possible to create a custom subroutine that allows you to control player 2 via a 2nd controller connected to port 2. Though I'm not really sure. Highly unlikely but still worth a try..
5. Ad libs code? Obviously a must for US & PAL versions.