Ativar Cheats Menu:
While playing, hold L1 + R1 then press Square, Circle, Triangle, X, X

Full Health:
At the Cheat Menu, hold R1 + L1 then press Triangle, Square, Square, Triangle, X, Circle.

Full Ammo:
At the Cheats Menu, hold R1 + L1 then press Circle, Circle, Triangle, Square, X, Triangle.