Took my 01 BMW 740i for smog check. Diagnostics listed about six codes, all sensors. Was told car had a misfire?? The car turns on, but it stales like its runing out if power gas and then all of a sudden takes off as I'm trying to push more gas like a bat out of hell!! Wen its jst parked it kinda shakes a little.when I have extra cash I fill up the tank and it'll drive fine.... Gas is low so ill fill it up again n it'll start acting up again for a few weeks. its a demon car!! I only had money to replace the camshaft sensor n that helped for awhile..now car recently made a loud hissing noise n stopped stalling but water is leaking or sumtin cause its overheating quickly. Goes thru coolant like crazy! Please tell me way could b the problem so I can figure out how much ill have to invest in it before I can get rid of it.