Vacuum line on 2004 Chevrolet Monte Carlo

I have been experiencing "bucking" when the car is in motion after idling at a red light for some time. Advanced auto parts suggests this may be the problem-any others had this?

2 answers
Did the auto parts store check for an diagnostic trouble codes stored in the engine control module? If so, what were they? With these codes I could provide better info.
I have a 2004 as well and am having the same issue, I was wondering if you found the problem??