I still get a thrill hunting down old-school cheat lists late at night, and for 'Grand Theft Auto: Vice City Stories' on PSP there are a few reliable routes I always check first.
My go-to sites are long-running game communities like GameFAQs, IGN, Neoseeker, and CheatCC — they host user-submitted cheat codes and usually note whether a code is PSP-specific. You’ll also find handy writeups on Reddit threads and dedicated GTA wikis that show both the classic button-combo cheats (when available) and memory/hex-style codes used with PSP cheat plugins. If you prefer video, there are plenty of YouTube walkthroughs that demonstrate entering codes or using plugins step-by-step.
If you want to run cheats on an actual PSP, look into CWCheat (a homebrew plugin) — people compile text files of codes you can drop into the plugin folder. On emulators like PPSSPP, cheat support is often built in and easier to apply. Just be careful: messing with saves or using unofficial firmware has risks, so back up your files and only use codes from trusted sources. Happy chaos in Vice City, and don’t crash too many speedboats!