Recently their has been an error trying to log into Matchmaking/ aka Multiplayer for MW3, and so I've heard most of the cases have been fixed.(Including mine) But the thing is, I don't want this to go un-appriciated. I would love to thank Activision for coming to our needs and sorting out the problem with the Internet providers. (^_^) So Activision, We thank you.

-The COD community.

(P.s if your still getting an Error cod, reset your internet, reset your playstation(Turn it off and on) then wait a coulple of minutes before you re-connect to your interent then Matchmaking/aka Multiplayer. If this still does not help, please give it time and with in 24-48 hours it should be fixed, But it's most likely it will be fixed much sooner then 48 hours.