I was driving on the motorway earlier today and went to overtake another car. I put my foot down in 6th and it started to judder and then the management light came on and started flashing. Now the engine is shaking like crazy and is misfiring. I can't even drive it things are so bad. The only code showing is D900. The car is a facelift Mountune ST. I've used the search function but there doesn't seem to be an snwer. Anyone??