Something very strange happened today on the way home from work (19 miles trip mainly motorway). Firstly I was stuck in start stop traffic for about 4 miles. Then 12 miles nice and clear motorway. When I've reached my town and I stopped on traffic lights revs didn't drop to 600 as they usually do. They stayed at around 800 and the engine was shaking badly. It kept doing that at every light. No lights on dashboard. The revs gauge didn't jump much (maybe tiny movement hardly noticeable). About a month ago I've banked my egr (only via software) and had swirl flaps removed. Although I don't think it has anything to do with it.