I just got an AR yesterday and I can't find the wanlk through walls code...

Look right in the action replay section, almost at the top of the list is the code for walkthrough walls, and no you can't use gameshark codes on an action replay.

I don't know the code but you can't use gamechark codes for ARs because they're too long. And don't forget the master code otherwise the code won't work.

Be careful, ok. I've heard that particular code can mess up your game, and if you're new to AR, you may mess up and not realize it until it's too late, HINT-never save with a code on until you've checked all to make sure you didn't screw up something in your bag or the PC, because once you save it, it's restart or live with it(often not possible!). Also, never use too many codes at once because it'll freeze up your game. Just the ones required if possible, like the Master code, maybe a dma disable, and the code you want to actvate. They're fun, but don't lose all you stuff trying to do something-you'll regret it! But, have fun, and good luck with it. Try the warp codes to the islands and forget the tickets, just turn off the AR once you get there or you'll just keep warping to the same spot, then you can do some really cool stuff and catch some incredible pokes!