I have a egr flow problem I have replaced everything and still get the po401 code. I looked how to test my dpfe and what I read and see is that the voltage is suppose to rise but it drops on mine dose that mean its bad everything else works as it should. Its my third dpfe the the voltage has drop in stead of raised can all three be bad.
I had two different sensors come out the box bad. Highly unlikely, but not impossible. Sent from my iPhone 6 using Tapatalk