The PSP modding community is still alive and well. For more codes (like enemy pointers, custom jutsu mods, or texture swaps), check:
Follow these steps to start using cheat codes: naruto shippuden ultimate ninja impact cheat codes ppsspp
Below are tested, working codes for the USA (ULUS10589) version. For EU versions, the codes are slightly different—look for ULES01529. The PSP modding community is still alive and well
Never die in the middle of a 1000-enemy battle. Follow these steps to start using cheat codes:
_C0 Infinite Health
_L 0x2031E648 0x000003E7