Well, after picking the car up, I got a check engine light. He diagnosed it again and the error code P0190 came up, for the fuel pressure sensor. That is the part that was replaced. He turned it off and removed it. This morning, when heading to work my check engine light popped up again. The initial problems I was having were gone, bar some minor shaking when idling the cold engine that seem to go away once the engine is all heated .