Explorer'97 Troubleshooting P0401 but replaced EGR valve

ok the dpfe sensor (egr position sensor) is around 30 bucks and the vacuum solenoid is around 20 dollars. change both and then take the egr valve back off and clean the ports in the intake where the egr bolts to it. it has filled full of carbon. use a pipe cleaner and some intake and throttle body cleaner to clean out and then reinstall the egr and install the new parts. walla you have little money in the car and your problem will be fixed. if you take it to a shop you'll pay around 450 bucks