Car has stalled 3 times already - the car starts out fine, then loses power. Speed starts to decrease to the point where it gets to only 3 mph, and most of the noise I hear from the exhaust a really loud metal banging noise. Already spent $800 on car - car is running lean. I had mass air flow sensor replaced and that is not it, had a tune up done, and that is not it - had work on muffler done, and is not it. I could be anything, vacuum hoses, manifold gasket, fuel pump, intake manifold gasket.