On a stock PCM, it's either a vacuum leak (highly likely) or bad MAF (highly unlikely). My wife's car (an 05 impala) threw that code off and on. Her airbox had been knocked loose from intake hose just a crack, and under heavy acceleration is would suck in air past the MAF. Took me a while to find it.
Our cars have a lot of places where hoses can crack or come loose, you just have to systematically go through them.
I had a very small boost leak, where the stock hot pipe came into the intercooler, but was supposedly not what was causing the code to pop up. Mine turned out to be a bad cell in the battery and the SSAFC was acting up. I erased it and it would pop up again within a day, then I replaced the battery and it hasnt come back since.