EGR code po401

My truck has recently not passed an emmisons test due to a po401 code. My husband and I took off the EGR valve and cleaned it. We have checked the vaccum lines and they have vaccum but not much. The wires going to what we think is the solenoid have power. We had someone clear the code for us so the light would go off. It did for about 50 miles then came back on. Would you suggest the solenoid or the DPFE sensor? If the DPFE sensor where is it?? What does it look like? On here somewhere someone said there was a recall on DPFE is that for F-150 4.6? Thanks mommaduke

The dpfe sensor pretty much centered and a little to the driver side. It is a plastic rectangle piece with two vaccum lines goind down to an exhaust line coming off manifold. Those lines need to be checked to see if there clean inside mine was gummed up.I actually bought a dpfe sensor put it on still same code came back. I like u cleaned egr and checked everything twice. Broke down got egr that was fix i would try egr first.

It's been a while since your post not sure if this was done on your vehicle if you checked vacuum lines and replaced DPFE sensor you should take off throttle body and clean EGR ports on it not real complicated but most likely will fix that problem.