Hi, Last week I was at the workshop where they changed a fuel injector and a few spark plugs in my 2012 A1. For a while everything was working fine but a few days ago I started having some issues while maintaining constant speed. The engine starts coughing like there was a sudden lack of fuel. It last for a second or two, I can feel a sharp pull and then it keeps riding but the situation repeats itself two or three times before calming down. It never happens when accelerating or braking. I returned to my mechanic but they said everything is fine and that there are no error codes from the engine. Does any of you have any idea what could be going on?