1999 Ford Taurus NO Check engine light?

The light will say "SERVICE ENGINE SOON" and it is located in the lower left corner of the cluster right below the door ajar light. If you turn your key to ON without starting the car, the light should stay on (this is how to check to see if the bulb is operating). The emissions people check to make sure it illuminates when you turn on your car. Look on page 6-7 of your manual. So it could be a bulb or a wire issue. Your code is for the Differential Pressure Feedback Electronic (DPFE) Sensor. They generally get clogged with dirt or the membrane wears out. Since it is only a $40 part and it takes 5 minutes, I would just replace it and clean out the hoses. Once you get your light working and replace your sensor you should pass emissions.