The following are known Action Replay Codes for Need for Speed Underground on Sony Playstation 2 (PS2). These codes were also known as GameShark Codes and in most cases will work on both devices.

Device Compatibility: Action Replay & GameShark (Version 1 & 2)

Master Code – Must Be On
0E3C7DF2 1853E59E
EEA3E162 BCE4B0F2

Max Cash
DEB42482 C19E7B82

Max Circuit Starts
DEB3A502 C19E7B82

Max Circuit Wins
DEB3A50E C19E7B82

Max Circuit Style
DEB3A50A C19E7B82

Max Style
DEB49C6A C19E7B82

All Races Won (1)
DEB435E6 BEAB9D85
DEB435E2 BEAB9D85
DEB435CE BEAB9D85
DEB435CA BEAB9D85
DEB435D6 BEAB9D85
DEB435D2 BEAB9D85
DEB435DE BEAB9D85
DEB435DA BEAB9D85
DEB435E6 BEAB9D85
DEB435E2 BEAB9D85
DEB435EE BEAB9D85
DEB435EA BEAB9D85
DEB435F6 BEAB9D85
DEB435F2 BEAB9D85

All Races Won (2)
DEB434FE BEAB9D85
DEB434FA BEAB9D85
DEB43486 BEAB9D85
DEB43482 BEAB9D85
DEB4348E BEAB9D85
DEB4348A BEAB9D85
DEB43496 BEAB9D85
DEB43492 BEAB9D85
DEB4349E BEAB9D85
DEB4349A BEAB9D85
DEB434A6 BEAB9D85
DEB434A2 BEAB9D85
DEB434AE BEAB9D85
DEB434AA BEAB9D85
DEB434B6 BEAB9D85
DEB434B2 BEAB9D85
DEB434BE BEAB9D85
DEB434BA BEAB9D85
DEB43446 BEAB9D85
DEB43442 BEAB9D85
DEB4344E BEAB9D85
CEB4344A BCA99D85

Unlock Performance Options
DE4E28B6 BCA99B84

Unlock Visual Options
DE4E286E BCA99B84

Unlock Tracks

All Circuit Tracks
DE4E2826 BCA99B84

All Sprint Tracks
DE4E28DE BCA99B84

All Drag Tracks
DE4E2F96 BCA99B84

All Drift Tracks
DE4E2F4E BCA99B84

Unlock Cars

Nissan Sentra
DE4E2F3E BCA99B84

Mitsubishi Eclipse
DE4E2FF6 BCA99B84

Nissan 350Z
DE4E2EAE BCA99B84

Toyota Celica
DE4E2E66 BCA99B84

Nissan Skyline
DE4E2E1E BCA99B84