wekilled 
Two other possibilities are:
Intake gaskets
Clean MAF sensor
Another thought, I had the same codes & thought for sure it was intake gasket related.
I replaced my intake gaskets (which were visibly cracked) only to throw the same codes after putting everything back together.
A little more digging & I found that the little sensors in the MAF were covered in a sooty residue from K&N oil. A quick blast with some MAF cleaner & I've been CEL free for almost a year.
