I'm getting the P0191 code, there are several possible causes, I just want to know what is the most likely. The car started sputtering when I had low gas, I then bought new gas but immediately afterward it stalled and took awhile to start. Now it is running normal but check engine remains. It is possible that fuel pump, filter, rail pressure sensor or regulator are cause. I had the PCM replaced in the car a year ago, and I read these can also have problems with programming.