Crysis 1 Cheats/Mods

I was wondering if anybody had success making the PC cheats/mods work on PS3.
I've edited the system.cfg file but I don't get any results ingame...
Also I've located the difficulty files inside the gamedata.pak file, edited them and replaced them but once I boot the game I get a warning message that the gamedata is corrupt and i need to go back to XMB and delete my gamedata etc...

Please tell me if you have any ideas...