Could be a vacuum/air leak somewhere in the intake, and check the MAFS...those two seem to be a common cause that trips both banks running rich. Check hoses and connections. Not sure about your last two, possibly related, maybe not.

If your new to the online forum scene (we all were at one time or another), here's a tip on forum etiquette - its always a good idea to introduce yourself in the new member section before diving into a 'here's my problem' thread. Please stop by there and say hello when you get a chance, ok?