Hi everyone...I have a 98 A8 in great condition EXCEPT that out of nowhere it died on me as I was driving on the highway (I guess that doesn't sound like great condition)
According to the code P0321, I need a crankshaft speed sensor...does anyone know about this???

 

There should be a magnet on the fly-wheel, and a pick-up
coil sensor, that reads a pulse when it passes.

 

Now the dealer is telling me that it is my fuel pump (a $800 part) & that code probably because my car died & not necessarily why...I don't know what to do or who to believe!!!

 

Tell them to prove it, no gas will come out of the fuel feed line when the key is turned on if the pump is bad. Both of those will cause a no start condition, the crank sensor tells the ECM when to fire the spark plugs, and the fuel pump of course supplies fuel.