Audi Repair Questions? Ask a Mechanic for Answers ASAP
It sounds like you have blown one of the hoses off- it is probably visibly in place, but if you pull on it will probably move in/out of position. This throws off the Mass Air Flow sensor (MAF), since it is then getting unmetered air. The smoke would be a symptom of that.
Check any hoses that don't have a clamp, but instead have a metal end with a "clip" that holds the other "male" end of the other hose in place.
2008 audi A4 convertible - the soft top does not close.