Select "Options" at the main menu, then choose "Player Profile". Select the "Cheats" option, then enter FITS as a case-sensitive code.
All tracks
Enter WHATEXIT as a code.
Fast racers
Enter ALLQUIKI as a code.
Free G-Ride ATV
Unlock a free G-Ride ATV if you have previous save data from Offroad ATV 2 (on the same memory card as the ATV3 Save).
Get Everything
Go into player profile. Then into enter !SLACKER!. This will unlock everything.
Ground stunts
Wheelie: Press Analog-stick Down while holding Gas.
Endo: While driving, hold Analog-stick Up and press Brake.
Bicycle: While driving, press Analog-stick Left or Analog-stick Right and R2.
Instant $1500
Enter the following at the Password Screen: +foodstamps+
Unlock all ATV's in training
Enter the following at the password screen: NOSKILLS
Unlock Music Videos
Enter the following at the password screen: ROCKNROLL