2001 Ford Taurus OBDII code

The easy fix, and hopefully the only one you'll need to do, is to replace the dpfe sensor which id located somewhere near the egr valve, probably has two small rubber hoses and an electrical connector, these pieces are notorious for failures, if you're not sure of finding it on your car, go to your local auto parts store, buy it and take it from there, hopefully this will fix your issue, if not, then there's a problem with the circuit, an or pcm, hopefully not. You'll also need to have your check engine light turned off, which means that your car will not immediately pass testing because the scan tool would indicate that the system itself has not run the necessary checks to ensure all installed emission related parts are doing their part correctly, the pcm requires, after check light reset, what are called drive cycles, which are certain parameters each system needs to run in order to check itself, this is done, in part, to prevent people from turning the light off in an attempt to pass testing if it is required by your state, as an example something as little as a loose gas cap, can cause the check engine light to come on, reason is when you start the car, the pcm checks the fuel system for leaks, by using, depending on car make and model, either and air pump to pressurize the lines and associated parts, or vacuum, to look for leaks large and small, in fact the system can discern between large and small leaks, as I always recommend, you should buy yourself a scan tool and learn how to use it, you don't need to go complicated with this, they sell them on here or your local parts store probably has several types, depending on how complex you want to go