Here's update on this error code... the fix was a loose air cleaner!!! on this model engine 350, the air cleaner has a very tight round neck that requires you to really hit it home hard, otherwise it will not seat completely. The neck was up about 1/2 inch and allowed air to enter and screw up the fuel mixture.
Once the air cleaner was seated firmly the DTC error codes went away and never came back!
By the way, the Dealer said the problem was the MAS and wanted $400 to replace it! I can just see him reseating the air cleaner and laughing all the way to the bank!
Esta resspuesta la encontre en otro foro en Ingles y se los paso tal cual. Suerte