Full ammunition:
Press Start to pause game play and press Triangle. Highlight 
the "Help Text" selection, hold L1 + R2, then press X + Triangle. 
A sound will confirm correct code entry. Select the "Return To 
Game" option to resume with full ammunition. 

Full health and armor: 
Press Start to pause game play and press Triangle. Highlight the 
"Help Text" selection, hold L1 + R2, then press X + Circle. A 
sound will confirm correct code entry. Select the "Return To Game
" option to resume with more health and armor.