Service engine light code p1400

Service engine light soon is on for 2 weeks on 2002 Ford Explorer. Autozone came up with code P1400, which says DPFE circuit low voltage. Probable cause is 1. failed DPFE sensor or 2. open or shorted circuit. My reading suggests that failed DPFE sensors on Ford Explorers are fairly common and pretty easy to replace which I probably will do before taking to a shop and incurring diagnostic charges and inflated parts cost. One place also recommends cleaning EGR valve and lines first which could also cause these problems. How do I clean EGR valve? Will I need some kind of gasket to put back on? Do I use solvent or manually remove or run something through the engine?(such as a fuel line cleaner) Is this EGR valve easy to remove for nonmechanic but semi-intelligent person. Any advice appreciated. Thanks

Here are the codes associated with a defective PDFE sensor. Assuming what you meant to post was code P0401, then first I would replace PDFE sensor. Most of the time that will fix it.

P0400 Exhaust Gas Recirculation Flow Malfunction
P0401 Exhaust Gas Recirculation Flow Insufficient Detected
P0402 Exhaust Gas Recirculation flow Excessive Detected

After further investigation P1400 is a PDFE Sensor Fault Code. My old OBD Code List did not show it. But still I would replace sensor first.