I own a 98 Ford Taurus. It just started idling fast. On the highway, with my foot off the gas, the car would stay at 65mph! On the way home I was forced to ride the brake. When stopped after a little while the idle would lower but then... kind of sputter. And then go off. I am afraid to drive it. What is wrong with my car and how do I fix it?

Try cleaning the throttle plate and throttle body with a spray can of throttle body cleaner and a rag. Ensure the throttle cable is not binding and moves freely. Afterwards, clean the air box and replace the air filter.