Hi, I'm the proud new owner of a silver tdi sport which I bought from an used car garage in Manchester last Thursday. I had to drive on the motorway for the first time yesterday and I noticed the emission control system warning light was on and when the car hit 70mph there was a serious lack of power which didn't reset until stopped car and restarted the engine. I phoned the garage who said it could be a faulty sensor and Audi's have a limp mode to protect engines when a warning light comes on. The warning light is still on but its driving fine but when it hits 70mph limp mode still kicks in. The garage have told me to take it in so they can check the fault code and sensors. Anyone experienced this problem? Thanks in advance.