I have an A3 1.8t sport with 40000 miles on the clock when it is started from cold it runs but sounds like it is missing when it warms up it is fine another problem that I am having with it is the engine management light keeps coming on,( fault 17544 Long Term Fuel Trim Add.Fuel, Bank1 System too Lean) it has had a new air mass meter just fitted to the cost of £200.00 pounds I am sick of this light any help please