Hide car
Finish all ten missions in mission mode to unlock The Homer car. The car is selectable in any mode by choosing Homer's picture at the car select screen.
Hide New Year's character
Set the system date to January 1 to unlock New Year's Krusty under the "?" at the character selection screen.
Hide Halloween character
Set the system date to October 31 to unlock Halloween Bart (dressed in a Frankenstein costume) under the "?" at the character selection screen.
Hide Thanksgiving character
Set the system date to November 22, 2001 to unlock Thanksgiving Marge (dressed in a Pilgrim costume) under the "?" at the character selection screen.
Hide Christmas character
Set the system date to December 25 to unlock Christmas Apu (dressed in a Santa costume) under the "?" at the character selection screen.
Mystery Clown Car
Turn on the system without a disc. Change the date to New Years Day and you will get a Happy New Years Car that is driven by Krusty the Klown.
More Money
At the options menu Hold L + R and press Y, Y, Y, Y. A sound will signal correct code entry.
Get Night Time
At the options menu Hold L + R and press A, A, A, A. A sound will signal correct code entry.
Get Overhead View
At the options menu Hold L + R and press X, X, X, Y. A sound will signal correct code entry.
Get More Camera Views
At the options menu Hold L + R and press B, B, B, B. A sound will signal correct code entry.
Get 2D Characters
At the options menu Hold L + R and press X, X, X, X. A sound will signal correct code entry.
Get Nuclear Bus
At the options menu Hold L + R and press B, B, Y, X. A sound will signal correct code entry.
Get Red Soapbox car
At the options menu Hold L + R and press B, B, Y, X. A sound will signal correct code entry.
Get Viewable Collision Lines
At the options menu Hold L + R and press B, B, A, A. A sound will signal correct code entry.
Get Smither's in Mr. Burns Car
At the options menu Hold L + R and press B, B, Y, Y. A sound will signal correct code entry.
Mission Skip
Intentionally fail a mission five times and it can be skipped. This cannot be done on the final mission.
Extra Time
To get +2 seconds, hit the bus stops booths that have Mr. Burns' picture on them.
Disable all Active Codes
Hold L + R and press Start, Start, Start, Start at the options menu. If done correctly you will hear a sound.
Slow Motion
Hold L + R and press A, B, Y, X at the options menu. If done correctly you will hear a sound.
Stop Time
Hold L + R and press B, Y, X, A at the options menu. Press Y to start, stop, and reset the timer. If done correctly you will hear a sound.
Turbo
Hold L + R and press A, Y, Y, A at the options menu. Hold and release X during game play for a turbo boost. If done correctly you will hear a sound.
No Map Display
Hold L + R and press X, Y, Y, B at the options menu. If done correctly you will hear a sound.
Flat Characters
Hold L + R and press B, B, B, B at the options menu. All the people (except the character you selected) will be flat. If done correctly you will hear a sound.