So Grand Theft Auto: Chinatown Wars was leaked a little early of the release date.
And as anyone with half a brain would assume it has some issues with most flash cards.
There was quick patches released to make the game run on carts like R4/DSTT.
While this was awesome, it also disabled wifi activity.
So anyway here is what you do:
~ Download a CLEAN GTA:CW from somewhere, try romulation.net or nds-roms.com
~ Download my Easy R4 setup >>HERE<<
Now that you have the files:
Put Grand Theft Auto Chinatown Wars (CLEAN) on your sd card.
Run YSMenu firmware and navigate to the game, press Y to enter the cheat menu and activate the fix.