Quake IV Cheats

While playing the game, press back to display the objectives window, then quickly press Down, Up, Down(2), Up, Right, Left, Right, Y, X(2), A. Your health still decreasebut will never reach zero.

Press back during the game and quickly enter these codes.
Get All - Up(2), Down(2), Left, Right, Left, Right, B, A
Full Health - B, A, B, A, Up(2), Down, X
Full Ammunition - B, A, X, Y, Left, Right, Left

Press Back during game play, then press B, A, X, Y, Left, Right,
Left.