so i was driving and my car started shaking and sputtering and my check engine line started flashing. when i drove out to bring it back to the shop (i had just got it back - there was a leak in some part of my coolant container so i had that replaced) it just shook even more and died out. i couldn't do anything...it just kept dyin over and over again. it's now back in the shop but what's the problem with it?! help pleaseeee!! -anna