Thanx steve 4 the reply. So do u think that a leak can caus a missfire which results in a shake? It could b. But i think the 1st mechanic would've told me if there was a leak. Also is it possible that the smell is of the fuel which is running down the exaust unburnt b caus of the missfire? I will check into it anyways. Can u please give me an idea about the location of the fuel pressure regulator? Thanx again.