Grand Theft Auto 3 (Xbox)

Note! If you save your game after using some of the codes, the effect of the code will be permanent.

All Weapons:
Black, Black, L, Black, Left, Down, Right, Up, Left, Down, Right, Up.

Full Health:
Black, Black, L, R, Left, Down, Right, Up, Left, Down, Right, Up.

Full Armor:
Black, Black, L, White, Left, Down, Right, Up, Left, Down, Right, Up.

Higher Wanted Level:
Black, Black, L, Black, Left, Right, Left, Right, Left, Right.

Lower Wanted Level:
Black, Black, L, Black, Up, Down, Up, Down, Up, Down.

More money:
Black, Black, L, L, Left, Down, Right, Up, Left, Down, Right, Up.

Invisible Cars:
L, L, X, Black, Y, L, Y.

Change outfit:
Right, Down, Left, Up, L, White, Up, Left, Down, Right.

Pedestrians attack you:
Down, Up, Left, Up, A, R, Black, L, White.

Pedestrians have guns:
Black, R, Y, A, White, L, Up, Down.

Pedestrians riot:
Down, Up, Left, Up, A, R, Black, White, L.

Improved car handling:
R, L, Black, L, Left, R, R, Y.

Blow up all cars:
White, Black, L, R, White, Black, Y, X, B, Y, White, L.

Gore Mode:
X, L, B, Down, L, R, Y, Right, L, A.

Clear Weather:
L, White, R, Black, Black, R, White, Y.

Foggy Weather:
L, White, R, Black, Black, R, White, A.

Cloudy Weather:
L, White, R, Black, Black, R, White, X.

Rainy Weather:
L, White, R, Black, Black, R, White, B.

Flying car:
Right, Black, B, R, White, Down, L, R.

Tank:
B, B, B, B, B, B, R, White, L, Y, B, Y.

Speed up time:
B, B, B, X, X, X, X, X, L, Y, B, Y.

Faster game play:
Y, Up, Right, Down, X, R, Black.

Slower game play:
Y, Up, Right, Down, X, L, White.

Explosives:
When you go to 8-ball's bomb shop, go to where the tunnel is very close to there. There will be four old men in there. Kill them. You will have some explosives. Now you can blow up cars easier.
(supplied by: pepitojoe2002)