alright, I recently changed out a "vanos" unit in my bmw 1999 328i. the engine dying symtoms went away, however, the car still has "rough" startups. basically, the engine shakes during the warmup process, a minute later, the check engine light comes up. I have noticed, turning the engine off and restarting it, the engine doesnt shake anymore, the light will stay on but goes away after a day or so by itself. any help?