3ds pin code

That sucks! Nintendo always have small issues like that. Shoot them an email and they should be able to take care of it for you. support nintendo com

You can also remove the Parental Lock Code online on the Nintendo Website you just have to pay $0.50 and need the Serial Number which is in the bottom of the 3DS and the Confirmation Number and you will get an email with the Master Key took me some time to figure it out and it was easy. Option 7 thats in the bottom.
http://en-americas-support.nintendo.com/app/answers/detail/a_id/2982

See this website for all the cheat codes for Mario Kart 7 (for the 3DS): Mario Kart 7 Cheats Codes Unlockables Nintendo 3DS IGN

Send it to Nintendo if your warrantee is still good. But if it's not, I have the solution. Go to Club. Nintendo.com., sign up, type in your serial number on your Nintendo 3DS, and you get another 3 months on your warrentee.

u need to check the bottom back for the code

23015288

Since you won't be able to utilize the secret questions settings (I am assuming this PIN and secret questions were created by the previous owner), this is what you will need to do:
Type in any code so that it prompts you that the PIN is incorrect. Now click on the secret questions option and enter anything. Now click the "iforgot" option. You will be provided with an "Inquiry Number" that you must enter at Nintendo's Customer Service site. (http://ds.about.com/gi/o.htm?zi=1/XJ&zTi=1&sdn=ds&cdn=gadgets&tm=261&gps=438_569_1276_778&f=00&tt=12&bt=1&bts=1&zu=http%3A//www.nintendo.com/consumer/systems/3ds/en_na/ts_settings.jsp%3Fmenu%3Dparental%2520controls%26submenu%3Dctr-ts-settings-parental-controls-forgot).

When your Inquiry Number is entered correctly on the website, you wil be given the option to join a live chat with Customer Service, or you can call Nintendo's Technical Support at 1-800-255-3700. You will need your Inquiry Number and the representative will give you a master code to over ride the existing PIN on your 3DS.
*****Be sure that before you retrieve your inquiry number that you ensure the date and time is correct on your DS. For some reason this can result in an issue if this precaution is not taken.

You have to connect your 3DS to a WIFI spot. Add the wireless router to your 3DS and confirm the connection. From here you will do a system update in the System Settings button.

The 3DS basically, can already connect to the internet as long as you have connection to WiFi. But if you want to browse using your 3DS, Do these: System Settings > Other Settings > Tap on 4 > System Update > Enter your PIN code > Tap on OK when you have internet connection > I Accept > Plug AC adapter (Optional) > Wait.
After waiting, You'll get the Nintendo eShop and the Internet browser. Reminder: YouTube, Other media can't be played or downloaded, Facebook chat is not available.

Hello Mike,
How are you?
Unfortunately, you can't. The procedure requires your DS to be connected. Please refer to this: http://www.nintendo.com/consumer/systems/3ds/en_na/ht_internet.jsp
Important! Your Nintendo 3DS must be connected to the Internet to perform these steps. 
Hope this helped!