Up, Down, A
All computer opponents will attack you only

Left, Left, A
All computer opponents will do
nothing

Left(x2), A
Disable AI

Right, Left, A
Infinite Nitros

Left, Right, A
Jumps enabled by pressing Y

Up, Down, Left, Right, A
Master Code

Right, Left(x2), A
No Nitros

Up, Down, Left, Right, A
Unlock all cars & tracks

All Cars and Tracks: Insert the gam disc, and as the game loads, press up, down, left, right, A.

Begin a game, and after you select a car and track, the game will begin to load. Enter these cheats:

Bot Gang Up: down, up, A
Enable Jumps: left, right, A
Infinate Nitro's: right, left, A
Kill A.I.: left, left A