The following are known Action Replay Codes for Star Wars Jedi Knight II: Jedi Outcast on Nintendo GameCube (GCN).

Master Code – Must Be On
PV9Y-QDY5-0JR33
XMB6-2XR3-6TPWP

Infinite Ammo
D26C-RA9U-Z56VY
2GWR-X6CA-K7PHQ

Start With Lightsaber
ADD9-NMXR-Y7M8G
JWQP-2N18-A561B

All Levels Unlocked
71GY-469M-0V2GH
AV9M-99GJ-9R1JJ

All Models And Gallery Unlocked
26JH-XJ67-BANZE
K63D-3TBW-WKBJA