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Ron Z.
Ron Z., - Ford Tech -
Category: Ford
Satisfied Customers: 18693
Experience:  18+yrs experience. State Inspector & Ford Diagnostics/Repair
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2002 Ford Explorer XLT: V6 4.0L - engine check light..flow

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2002 Ford Explorer XLT, V6 4.0L - engine check light. Error #P0401, exhaust gas recirculation flow insufficient.

In research, it sounds like the problem may be the DPFE sensor , which is supposed to be easy to change and cheap (~$30). I have not been able to locate it - supposedly screwed into the firewall. Does this seem likely? How do I locate & replace it?


The DPFE is a very common fail item with this p-code. Be sure to check the vacuum hoses to/from this sensor for tears or disconnections.The DPFE is on top of the engine near the EGR Valve, not on the firewall.


  • Disconnect the battery ground cable.graphic
  • Remove the accelerator splash shield.graphic
  • Remove the electrical connector and remove the differential pressure feedback exhaust gas recirculation (EGR) sensor.
Customer: replied 7 years ago.
The first diagram does not seem to match my engine. I am assuming the air intake in the large hose curving in the lower left. There is no box like that above the intake manifold. On the other end there is a box where the air filter is, but that doesn't match the look either. This is a V6 4.0L SOHC, but was rebuilt a couple years ago. Is there a way to forward a picture?


The top picture is just the plastic engine cover. Should say 4.0 on it. This needs to be removed. Maybe yours was never put back on? Can you give me the 8th digit of your VIN#?


If you need to send a pic to me, you can. Just upload it to the message via the little icon above that looks like a tree.



Customer: replied 7 years ago.
E looks to be what you are looking for.

Took a pic of the engine - trying to figure out how to attach. Is the 'share' button what you were referring to?


OK. That's the engine code i have in there. It should be there. In the message box you are typing into, there should be a list of icons across the top. It's 2 to the right of the yellow smiley face.


See if any of these help you. If you locate the EGR Valve, its right next to it.





While I was looking around, I actually found a Recall on the DPFE sensor for this vehicle. You can have it replaced for Free.



Customer: replied 7 years ago.

Ok - switched from Chrome to IE and now I see the toolbar. Chrome apparently strips that... weird.


Here is the pic of the engine well - that would be cool if the the sensor was to be replaced on recall! So do I take off the air intake hose on the right end to get to the sensor?



I pointed it out in the pic you sent me with a white arrow... black box, grey electrical connector. Make sure you check the 2 hoses on the bottom for tears, and make sure they are tightly connected on both ends.


Customer: replied 7 years ago.
Ok great - will do. Assuming the hoses are ok and not clogged I will get a replacement part tomorrow. I will also call on the recall tomorrow. I may not be able to wait for them however. Thanks so much for the info - I will get back to you. Wish I had used IE sooner...


The part is cheap enough, but if you can save a little money, why not! Above I sent a copy of the letter Ford sent about the recall, (Click "View Full Image" to get a close-up) there's a phone number in there.


Glad I could help! Have a great day!


Ron Z. and 2 other Ford Specialists are ready to help you
Customer: replied 7 years ago.

Thanks so much - very much appreciate your time. Hoses look good although I did not check them for clogging yet - will wait to take it off until I have the replacement part ready to go.



Sounds like a plan. More than likely that sensor is gone. If they went so far as putting out a recall on it, chances are, yours is no good.