I agree with vsapra, it might have something to do with the fuel system. I had this happened before....replaced the fuel filter then the issue has gone since. Here are the part numbers:
Fuel Filter: 16126750475 $74.28
Fuel Filter Hose Clam: 07129952104
The replace procedure is fairly easy...it's right underneath the driver side. Just take the plastic cover off then you should see it.