Diagnostic code P0401 Insufficient EGR Flow
 

My 2001 F-150 came up with this code and I changed the EGR valve cleared the code and it returned 15 miles later. Does any body know what else it could be? I appreciate any help the truck only has 30K miles and the warranty expired 24 May.

You need a dpfe sensor not the egr valve!

If your truck didn't have only 30,000 miles on it, I would take the egr valve back off, remove the throttle body housing, and clean the two egr ports and passage inside the throttle body housing. That is what cleared my low egr flow code. I've read alot of people replace the dpfe for this code and it doesn't help. You have the 4.6 V8? Ranger88 must be right.
Mine was closed up with hard carbon, cleaned at 128,000.
A guy posted a thread the other day, a mechanic wanted $900 to put in a new dpfe, which the guy did himself instead. Code still there. Good luck.

Thanks for all the suggestions. I going to do some cleaning then if that don't work I guess I will be replacing more parts. For FourthFord Truck I have the 4.2 V6. I've only had the truck for 2.5 months so I am not sure how the previous owner treated the truck. The truck is still running strong with no missing or hesitation. Thanks again for the suggestions.

I'm familiar enough with the 4.2 to know about the egr set up.
The DPFE won't take you long at all.

I would like to thank you FourthFord Truck I changed the DPSE sensor, reset the service soon light, and have driven the truck for 200 miles to my success the light has not returned. Thanks again.

Ranger88a deserves the thanks, but you are welcome Vegas. My submission seems
almost more confusing to me than helpful. Ranger88a was right on.
I meant to say I am not familiar enough with the 4.2 egr set-up.
I will remember the false egr code on lower mileage trucks as possible dpse trouble.
Thanks Ranger88a!

No problem, I work on them everyday, glad to help. There are many here who help eachother and many thanks to them also! :-X22

Thanks to you too Ranger88a. I greatly appretiate it.

check with your dealer on the dpfe... it has an extended warranty. You'll need to give em your vin # and mileage.

Code not always DFPE
 

Just to let you know. I got the same code (P0401) on my 97 4.6l F150, and replaced the DFPE sensor right away. Didn't fix the problem, so I'll be cleaning the EGR ports next. A lot of people have said that this code means a bad DFPE sensor, and it's not always true (actually, it seldom is from what I gather). Now I'm getting a P0302 (#2 misfire) code, which I think might be related. I've replaced the coil packs and the plugs, and will replace the wires next.

On a high mileage 4.6, I would always go with the egr ports and valve.
I believe every 4.6 will eventually have this problem.
On a low mileage 4.2, I'd go with the dpfe.

Where is the most inexpensive place to purshase a DPFE sensor? My local dealer wants +/- $100

Got mine on ebay
 

There's a couple due to close in the next day or two. Just do a search for Ford DPFE and you'll find them.

I just had to replace the DPFE sensor on my 99 rangertoday.Is this a common problem?