All Cheats
You can only enter these codes by making a game in single player, press start, and then enter these codes using the D-pad. You will hear a confirmation sound for each code you enter. However these codes cannot and will not will work on Xbox Live.
Low Gravity: Up,Right,Right,Up,Up,Left
Bots don't shoot: Left,Right,Right,Left,Up,Down
Bots Glow (Terrorist = Red, CTs = Blue): Right,Right,Right,Up,Down,Left
Big Heads: Up,Up,Left,Right,Up,Down
Clipping (Can got through walls, Only for you): Up,Down,Left,Right,Down,Up
AutoAim (yes AutoAim): Down,Down,Down,Down,Up,Up
$16000: Up,Up,Down,Down,Left,Right
Switch Outfits (Although it may seem different to you, the bots know who you are =): Left,Right,Down,Up,Left,Right

Unlimited Ammo Enter these codes: A, X, Y, B

Tip: Move Faster Using the knife or handguns allow you to run faster, this comes in very handy when rushing to a sniper spot or ambush point before the enemy can get there. Also when throwing grenades or flashes if you hold down fire trigger then jump and release, your nades will go further, also using bankshots off of walls places flashes out of your eyesight easier. On Italy you can "teleport" in various spots on map. Using a partner in the wine cellar get on to highest crate, and have partner crouch on lower crate, jump on his head and both start jumping repeatedly and you can go through the ceiling and you appear at terrorist spawn point that is directly above that position. There are at least 4 different places in that map that it can be done. Have fun!