Pulled the P0446 code on my 2004 Escape. After searching the threads I decided to change the DPFE sensor. Code came right back. Today I started tracing vacuum lines and when I got under the truck I found the problem right away. The vapor cannister which is mounted under a protective shield in front of the fuel tank and fuel filter has a sensor with 2 wires going to it. Apparently a squirrel or something had chomped both wires clean through. I spliced the wires back together. Hopefully that's the end of that code.
Wow, that was good eyes, sounds like you found the cause of that code, let us know if the code comes back on.
Oh.... one problem with getting rid of squirrels....don't let anyone kid you, they really don't taste like chicken! Now rattlesnake....well that's some good eating, good thing though rattlesnakes don't care much about wiring, they do enjoy a nice warm engine compartment though. Take care!