What would cause my vehicle to stutter and die at stops and while low speed cornering?

For the last couple months my car has started to stutter and die at stops and during low speed cornering. The car seems to be fine while accelerating or at speed. I have changed oil, replaced plugs, plug boots, air and fuel filters. The months prior to all of this I had noticed a drop in mpg performance. The above actions have seemed to correct this but I am now left with the car still dying. I went to AutoZone and they ran a code check and it returned code P0172. Any ideas? Thank you in advance.