Help PO401 code

My 2001 exploer PO401 insuficiant egr air flow I don't believe the egr control valve is being signaled to send vacume to the egr valve. Iv'e checked and have a ton of vacume to the control valve but nothing after I removed the egr to clean it and found it working fine.I checked the resistance and voltage at the control valve and found them in spec. The cold voltage at the dpfe sensor was lower than the spec I have(0.12 v spec I have is 0.8-1.2v) but after engine warm up is good (spec 4-6v I got4.8-5.2v) Could the cold voltage be a problem? Or do I have to look else where. If any one has had the same problem or can help I'd be forever greatful. The truck run"s allright but the check engine light id iritating to look at. Thank"s in advance Yoddy

Welcome to the forum!

Which engine do you have? Did you check the EGR passages between where the EGR valve mounts and the throttle body/intake? If those are plugged, they will restrict EGR flow. Chances are the DPFE is the issue though.

-Rod

I have the 4L sohc engine Rod,and thank you for the reply. I think I will change the dpfe next it dosen't look expensive. If that dosen't do the trick I'll take the valve off again on the weekend and check that the throttle body is clean. This all crept up after the vehicle was brought back out of winter storage. Thanks very much for the tip I really apreciate it Yoddy