Mario Kart Wii Code Problem?

it has to do with the homebrew channel, i installed cheat engines on it and only the no lap cheats are working, i can’t use any items in any mode whatsoever and no matter how i try correcting the codes in the game to use items I JUST CAN’T GET THE CODES TO ACTIVATE
some of the codes won’t even turn on, i have a code downloader on the homebrew channel, and thats what i use to get my codes,when i open the codes up with my cheat manager, most of them don’t even work, i press the + button like it says to turn the cheat on, but it will NOT turn on, even with all values correct and all things modified to make the code work
SOMEONE PLEASE HELP