How to Hack Mario Kart Wii Online for Unlimited Items Including Blue Shells

Update: looks like it's easier to cheat nowadays. If you install the homebrew channel, you can enable cheats from there. I don't know the specifics, so feel free to leave a comment if you know any more than that.

Update (6/19/09): from reader Rosalina, you can indeed hack it from the homebrew channel:

Materials:
A Homebrew Channel on your Nintendo Wii
An SD Card
Ocarina in your SD Card
Legend of the Twilight Princess for Wii

Use Legend of the Twilight Princess game to get Homebrew Channel and then
Go to File and then open TXT file. Then select rmce01 is Mario Kart Wii's ID. Then go to add a code/comment. Type in as many as you want but make sure you call it what it is called in the Mario Kart Wii Instructions Manual. And make sure you put “Infinite” before the power you want (the most fun powers are Star, Mega Mushroom, Triple Red Turtle Shells, Triple Green Turtle Shells, Bullet Bil l(the rocket) and some time Triple Banana, Fake Item Box and Bomb-omb.) OK? Now type the codes in the code box {codes are at www.usbgecko.com/codes}. Insert the SD Card into the PC and then go to 'Export to GCT' and select your SD Card. Insert the SD Card into your Wii and go to the Homebrew Channel and press start. You will be able to hack Mario Kart on the Homebrew Channel. My guess to stop hacking Mario Kart is to take your SD Card out of your Wii.

This information is out of date, but I'll leave it here for posterity:
I did some digging and this guy who goes by the handle /dexter0 (aka ihack@you) appears responsible for this nonsense (46 pageviews when I accessed it), but I could be wrong. It appears this hack is accomplished using a USB Gecko attachment, which is pretty much like an Action Replay or a GameShark.

He basically just edits the database values that represent your item box status to choose what item you have at any point (resulting in unlimited items).

From /dexter0 (aka ihack@you):

These codes were hacked under NTSC-USA. And since they involve assembly hacking, they are not easily ported. So don't ask for PAL or JP codes.

[Write Char Offset]
D27E4DDC 00000002
3FE08000 93BF1500
3BE00000 00000000

[Always Have Item *Works anywhere] - Add Your Own Button Activator
48000000 809BEE20
DE000000 80008180
58010000 00000014
DE000000 80008180
48100000 80001500
DE000000 80008180
1400008C 000000XX
14000090 0000000Y
E0000000 80008000

...you need both of them for it to work. The Write Char Offset must come first! And don't click the apply button while a race is active, you'll crash them game.

Have fun. Try not to be a dick.

If you wish to report a cheater, drop a comment on my Wall of Shame page with their name and a description of their Mii (if available).

Posted in: blue shell,cheat,hack,mario kart wii,unlimited items,usb gecko