1999 Ford Taurus 3.0 v6 DOHC 24v SE model, getting Code P0401 EGR insufficient Flow?

I have this code currently in my car. I had disconnected the air box and cleaned the throttle body out with cleaner. I also removed the EGR valve to clean the area as well. I had replaced the EGR valve and the EGR vacuum solenoid and cleared the codes. A couple of starts and driving the code comes back and the check engine light comes back on. So currently the code is on and im getting very frustrated with this and I need some advice or help. I am thinking the next step is the DPFE sensor is the next step but I don't want to spend more money if its fine. There is a Technical Service Bulletin on the EGR Valve with that Code and im not sure if Ford will at least Diagnose the problem for free. PLEASE HELP ME!