Hi all... I've browsed over to some of the other posts (via the search tool) to find out some information on this. I've had the A6 for a couple of weeks now, and today the Emission Control System Fault light appeared in the dashboard. It's a 54 car, but it's only covered 29000 miles. I need to know what the worst case scenario is. I've not noticed anything wrong with the running of the car since the light came on, so I'm assuming it's nothing too serious, but still I don't want to be hit by a massive bill at Audi! Can someone give me an idea of what to expect? Cheers! A.