When my cobalt was under its warranty they told me I had a bad connection to the MAF sensor, which was causing my CEL to be on, and of course the rough idle and jumpy shifting.
So, if it was the MAF sensor, I would guess the CEL would be on. I hope its as simple as a bad connection to the MAF, but its seems unlikely to me, going by my experiences and the words from service at the dealership.
Assuming your CEL is off, if its on, get free scan at autozone or which ever auto parts store offers this for free.
Old Car: Chevy Cobalt 2006 LS Sedan base (Automatic)
New Car: Chevy Impala 2011 LT Fully Loaded (Automatic)