Full health and armor 
Pause the game and press Triangle. Then, highlight the 
"Help Text" selection, hold L1 + R2, and press X + Circle. 
If you entered the code correctly, you will hear a sound. 
Now select the "Return To Game" option to resume with full 
health and armor.

Full ammunition 
Pause the game and press Triangle. Then, highlight the "Help 
Text" selection, hold L1 + R2, and press X + Triangle. If you 
entered the code correctly, you will hear a sound. Now select 
the "Return To Game" option to resume with full ammunition.

All items 
Pause the game and press Triangle. Then, highlight the "Help 
Text" selection, hold L1 + R2 + R1 + Square and press X. If 
you entered the code correctly, you will hear a sound. Now 
select the "Return To Game" option to resume with all items.