Check your IACV. The gasket may be broken. Or you may need to clean it. Make sure that you have a spare IACV gasket handy though. I threw a similar code in the summer. Cleaned my IACV and it went away.
Any recent mods?
If you ran a scan with a Cobb Accessport make sure your connections were correct with the Accessport.
Also, when you clean your MAF, clean the two little wires inside too.