Last week I took my car in to get several oil leaks fixed, including a gasket they had to take the entire thing apart for, and spent 15 hours on. 3 days after it was fixed, I start driving and the car starts jerking and the check engine light comes on and starts blinking- I slowed down, but even at idle it was running roughly, still jerking, etc. It finally settled out but the light remained on. Today, I turn it on and nothing. Smooth running and no light. I find it something of a coincidence this happens three days after the engine was just partly taken apart. I have previously replaced spark plugs and ignition coils, and the symptoms reminded me of the spark plugs, like a fuel injection issue, but I don't know enough to really know. Could this have something to do with them putting it back together improperly?