ok heres some cheats, if it involves cars then do it in a car if not then just whilst standing there:)

Blow up your car: L2 R2 L1 R1 L2 R2 Triangle square circle triangle L2 L1.
Blow up all cars:L2 R2 L1 R1 L2 R2 triangle square circle triangle L2 L1.
Full Health: R2 R2 L1 R1 left down right up left down right up.
Full Armor:R2 R2 L1 L2 left down right up left down right up.
All Weapons:R2 R2 L1 R2 left down right up left down right up.
Lots'o'Cash:R2 R2 L1 L1 left down right up left down right up.
Invisible Car:L1 L1 square R2 triangle L1 triangle.
Speed The Game Up:triangle up right down square L1 L2.
Slow The Game Down:triangle up right down square R1 R2.
Jumping Car:R1 L1 R2 L1 left R1 R1 triangle(then R3 to jump)
Wanted lvl up:R2 R2 L1 R2 left right left right left right.
Wanted lvl down:R2 R2 L1 R2up down up down up down.
Weather Cheats: Clear:L1 L2 R1 R2 R2 R1 L2 triangle.
Fog:L1 L2 R1 R2 R2 R1 L2 X.
Cloudy:L1 L2 R1 R2 R2 R1 L2 square.
Rain:L1 L2 R1 R2 R2 R1 L2 circle.

Tank:circle x6 square square R1 L2 L1 triangle circle triangle.
Dodo Car:R1 L1 R2 L1 left R1 R1 triangle,
Flying Cars:R2 circle R1 L2 down L1 R1.
Warningpedestrian cheats cannot be reversed so do not save after using them.

Pedestrian riot: R2 R1 triangle X L2 L1 up down.
Pedestrians h8 you: down up left up X R1 R2 L1 L2.
Pedestrians Fight Eachother:down up left up X R1 R2 L2 L1.
Pedestrians all have weapons:R2 R1 triangle X L2 L1 up down.
Change Costume:right down left up L1 L2 up right down left.
Extra Gore (head and limbs fall off when hit):square L1 circle down L1 R1 triangle left X.
Shoot out car windows with uzi: L2orR2 cirlce.
Cool camera view:SELECT x4.

Glitches and Hints

get dodo car and flying car cheat and fly over calahan bridge.

get cool car and in red light district find one of luigi's prostetutes, stop next to them, if you have a good enough car, they talk to you and get in, drive to your hideout and stop, car shakes, your health may become higer (even if you already have 100!) and you lose a bit of cash, when they get out, kill them and get your cash back!!!

get a police car or taxi, drive to the subway station near the triad gang area. go slowly up the ramp on the side and you fall down, sometimes, if in a police car or taxi, you go through the cage and your in the subway, either wait for a train, or drive down the track in your car.voila, yer in staunton island!

never stop sprinting buy not holding X but repeatedly tapping it!

if these dont work, conatact me.

These are ps2 cheats and your on a pc forum