Tokyo Cop Special Police Enforcer? I used to own that game for a very short amount of time. No real codes that I knew of. Just using the code pad to save the game and continue when you get tired of playing.
Took only 3 days for around 5 of us (collectively) to complete the game from beginning to end. Shouldn't really need cheats, just look for the shortcuts as the computer does tend to use the same routes over and over.