A-Train

Unlimited money (Japanese version):
Press L1 + L2 + R1 + R2, then press Square + Triangle + Start at the title screen. The map selection screen will be displayed. Hold L1 + L2 + R1 + R2 and press Circle. A sound will confirm correct code entry. Pause game play and press Left, Right, Up, or Down to gain more money.

A-Train (Game Shark)
Codes Made & Tested on 1.86 Version Game Shark