My 2009 nissian quest will turn over try it start then bogs and shakes and dies!

Hello, Obviously they are incorrect, and what they should have said is "we can't figure it out". These engines are notorious for start and stall issues pertaining to the crankshaft and camshaft position sensors, but this needs to be verified through diagnosis. Since it is intermittent (it normally is), you should leave it with the dealership until they can make it happen, or just wait until it happens all the time. Sorry, I know that is not the answer you want, but with intermittent problems you only have so many options.