Circuit Breakers cheats and cheat codes for Playstation

Select any track
Play in single palyer mode and pause the game. Then, go to the "Sound" 
option, highlight the "FX Volume" option, and push L1 + L2.

Jumping cars
Choose the multi-player mode and choose a track and car. Then when the 
countdown that marks the start of the race begins, push the 
Circle + Left buttons. 

Faster engine
Choose the multi-player mode, then go to the track selection screen and 
push X + Square + Triangle + Circle buttons. 
If the code is accepted, an engine should appear on the screen.

Night racing
Hold L1 + L2 + R1 + R2 at the track selection screen until headlights 
appear in front of the car. If the code is accepted, a new symbol should 
appear on the track.

Upside down tracks
Press L1 + R1 + X + Down at the track selection screen. If the code is 
accepted, an arrow should appear on the track.

Reversed tracks
Press L2 + R2 + X + Down at the track selection screen. If the code is 
accepted, an arrow should appear.
or
Choose a track and push the Select button. Then, quickly hold X + Square 
as the cars enter the tunnel. Keep held X + Square and press Left or Right. 
If the code is accepted, the cars will turn around and go into the tunnel 
in reverse.