Before you start fixing anything you should check to see if the EGR valve is working properly. First, with the engine off, apply vaccum to the small fitting on the EGR valve to see if it will hold vaccum. If it dosen't hold vaccum the diaphram in the valve is bad and the EGR valve will need to be replaced. Next, with the engine at idle, apply vaccum to to the EGR valve the same way as before. The idle should drop, car will run rough, and may even try to stall. If it dosen't you either have plugged EGR passages or plugged EGR tube. A plugged tube seems to be very rare in the Contour, but plugged passages are very common. If the engine does run rough you will need to replace the EGR presure sensor. They cost $50-$75. There are many posts like yours in the troubleshooting forum, and also a good post about cleaning the EGR passages. Good Luck!
