my car dies while ideling.also while sitting still,my speedometer might show up to 40 mph, then back to o.
Your VSS( Vehicle Speed Sensor) is faulty. This will cause the symptoms you stated. Here is a video showing how to remove it if your handy with a wrench.
http://www.youtube.com/watch?feature=player_detailpage&list=FLQPoRsLtaktCTa0mjxOgcrQ&v=y0823ZDqxiU#t=118s Your Taurus might be slightly different.
Looking for a Used Taurus in your area?
CarGurus has 21,034 nationwide Taurus listings starting at $1,800.
Search Ford Taurus Questions
Are you a UK consumer? CarGurus now has a discussion forum in the UK.
Ford Taurus Experts