Jeremy McGrath Supercross World

Unlimited turbo:
Press Down(3), L, R, Z at the main menu. The lower left corner of the screen will flash and the message "Need for speed" will appear to confirm correct code entry. Repeat the code to disable its effect.
Dylanchaos5.

Moon gravity:
Press Left, Right, Up, Down, B(3) at the main menu. The lower left corner of the screen will flash and the message "Feel lighter" will appear to confirm correct code entry. Repeat the code to disable its effect.
Dylanchaos5.

Bouncy bike:
Press Up(3), Y(2), X(2) at the main menu. The lower left corner of the screen will flash and the message "Bouncy, bouncy" will appear to confirm correct code entry. Repeat the code to disable its effect.
blinkfreak2002.

Big heads:
Press B, X, R, L, Right at the main menu. The lower left corner of the screen will flash and the message "Your head expands" will appear to confirm correct code entry. Repeat the code to disable its effect.

Tiny mode:
Press L, Z, Left, Right, B(2) at the main menu. The lower left corner of the screen will flash and the message "Drink me" will appear to confirm correct code entry. Repeat the code to disable its effect.

Tag mode:
Press Z, X, Z, X at the main menu. The lower left corner of the screen will flash and the message "Tag you're it" will appear to confirm correct code entry. Repeat the code to disable its effect.

No boundaries:
Press L, R, Z, L, R, Z at the main menu. The lower left corner of the screen will flash and a message will appear to confirm correct code entry. Repeat the code to disable its effect.

Hint: All bikes:
Successfully complete the hardcore part of career mode.

Glitch: Get inside pyramid:
First, go into Baja mode on the course with the palm trees. Crash directly into the pyramid (with the domino-like objects around it) stairs. When, you get back up, quickly get on the stairs. If you do not crash, you will be climbing the stairs. Go up them at full speed and quickly pull the Analog-stick Down. You will die. When you get back up, you will be in the pyramid. Somehow a tree grew in it, probably something the programmers had fun with. You can also do this with the other pyramids, but this particular one is the easiest.
Michael Luaces.