Try a bottle of cataclean in the engine when your tank is about a third full. Take it for an Italian Tuneup on the way to the garage. Should see the emissions drop right down. http://www.ebay.co.uk/itm/Cataclean-Catalytic-Converter-Cleaner-for-Petrol-Diesel-475ml-/301105565304?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item461b4a4e78