Code P0401 “Exhaust Gas Recirculation Flow Insufficient” | Ford Explorer Forums - Serious Explorations

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Code P0401 “Exhaust Gas Recirculation Flow Insufficient”


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October 1, 2020
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2010 Explorer XLT - 4X4

I hope this thread finds you well.

EGR was recently replaced because the old one was bad. Code for bad EGR cleared but didn’t last long.

Instead got P0401 for Insufficient Exhaust Gas Recirculation Flow, and the vehicle will lose power on low RPM’s. Anything below 1,800 RPM’s with a load will make you feel like the vehicle is about to stall. The RPM’s will drop and the vehicle hesitates to move until you hit the gas further and will take off with no other issues whatsoever. Spark plugs and cables were replaced, Coil pack was tested and OK, gasoline injectors are also running well. Only code popping up is P0401.

Can you think of anything?

4.0 V6

I have had the same issue on my 5.0 X, only mine literally drives no different! No power loss shudder mileage loss nothing! That is also frustrating as it leads me no where as too the issue, i have cleaned it checked connections ect never helped light still came on. Now with that being said i made myself a new exhaust for it cat back, and as of almost 6 months now the light has not come back on. It used to come on at least once a month if not more. I have no idea why that seems to have solved the issue but hey do not fix what is not broken some times. I punched out the rear cats left upper two alone and ran 2.5 inch pipe from cat flange back and dump in front of rear axle. Sounds decent, quite unless romping on it and for some very odd reason fixed my light even though that had zero reason for my modification. I hope this helps, Maybe cat was starting to get clogged and didnt allow o2 to see something i dont know, the cat did not look all that bad visually that i beat out. Best of luck!

P0401 Insufficient Exhaust Gas Recirculation Flow

Is usually a faulty DPFE
Differential Pressure Feedback EGR (exhaust gas recirculation)

This is assuming the rest of the EGR system has been inspected, no leaks or broken lines, cracked hoses.

You said the EGR system was "recently replaced" well which parts? There is the EGR valve, the EGR line, the EGR gaskets, the DPFE and lines and the vacuum switch and vacuum lines

The DPFE is the most common part to fail and when it does you get either circuit failure code or incorrect readings like insufficient flow or excessive flow detected. Replacing the DPFE with a cheapo aftermarket part from Ebay or Amazon will only last a couple of weeks........ so it is suspect if you had a shop replace this part and they used a cheap one (they usually do, more profit)

If I recently had a shop "Replace my EGR system" I would want to look there first........what parts did they replace? Why did they replace them? What tests were done? Why am I having to do this again a couple of weeks later?

You may have more info on this and not to step on this guys thread, why would changing my exhaust have any effect on the light coming on for me? I just realized i had not had to turn it off for awhile and the only thing i have done is the exhaust. I also did the fuel pump but the light had already stopped coming on. Neither should of had any effect on it but hey it is still off drove it to town about half hour ago.