no is doesnt ruin your game.
but some cheats block soms achievements
I think you can, this is my favorite game for the PS2 and it auto saves even if you have cheats on, but I think you can save personally while cheats are on.
Of course not.
Yes after you enter one go to the bottom of the phone menu.
You go to your house (there is a picture of your house on the minimap) and when you see your bed, go towards it and press the save button. Easy
Just type it in once and go to your cell phone, the last option is cheats, the last cheat should be in there.
After you have used cheats, you can't get any trophies in that game save anymore.
to get a really rare pokemon, start the game, press new game and save straight after that
to select cheats when you are on the game you want to play press either X or B and on the top it should say: game, Cheat, save and ROM
yes you save and exit then go back into the game and if that doesnt work then something is wrong
You could use cheats on the Madd Dogg mission which is the last mission in the game. After that mission however, it would be impossible to use cheats.
i think the game is dirty or u used cheats for your game and it got screwed up
If you have it as a application on your phone or tablet it does.