My 'new to me' E90 335i started with a single misfire, then tragically cracked the valve cover during the polar vortex. While she was on the operating table for that [and cold weather] I took her to BimmerWerkShop in Beltsville Md. Amr did the work on the car. Outstanding results. Valve cover was replaced. Plugs and Coils Pictures of the blasting. - Before [all ports basically were this bad or worse] After All 6 ended up like this -Amazing transformation Off idle hesitation and part throttle responsiveness night and day .