Kattobi Tune Codes -

CPU control:
Press Start to pause game play. Press Select, then resume game play. Your car will now be controlled by the CPU. Repeat this code to return to normal control.

Full character attributes:
Enter the "Garage" screen in scenario mode and press Down(2), Up(2), Right, Left, Right, Left, Select.

99,999,900 credits:
Enter the "Garage" screen in scenario mode and press Up(2), Down(2), Left, Right, Left, Right, Select.