Can any one please guide me I have honda city 2001 m/t yesterday I changed it's generator through mechanic and after that my rpm is not working fine it drops down by 300-400 in idle position or when i ran my car and stop it suddenly also when i do my ac on it works fine but when i cloet it rpm drops down and comes up when i drive it goes fine when i stop rpm drops and comes up I asked the mechanic he said i have replace generator with little more power instead same previous one. Please guide me what should I do? Problem is when rpm drops my car is shaking too much. Sometimes it is standing on 1000rpm. Mechanic says drive it for 1-2 more days hope prob will be solved.