There is a very well documented issue with the MAF - search for "weak MAF" and you will find many posts on it. Here is one that also has links to how the issue was initially discovered and easily remedied:
http://www.camaro5.com/forums/showthread.php?t=195581
Basically, pull the negative battery connection, pull the MAF (careful not to touch the sensor areas) and see what code is on the MAF. See the above link for details.
I had the exact same issues described in this thread and they were immediately corrected with a "Strong" MAF replacement