The other day my Service Engine Light came on so I took it to Autozone and the code reader said P0401 Insufficient EGR Flow. The guy said it was a bad EGR valve. I replaced the EGR valve and the next day the light came on again. I went back to AutoZone and the guy said the problem was that I had driven it with a bad EGR after the code was reset, so he reset the code with the new EGR and the following day the light came on again. I am confused is the problem not the EGR. Any help would be greatly appreciated.

 

I had the same problem with my 01'. They guy at Autozone told me the code was P0401, and he said the code reader said "Insufficient EGR Flow". He said I problably had a bad EGR valve.

I remembered that I got a letter from Ford in the mail that said my DPFE "EGR sensor" may be faulty, and may fail. So Ford extended the warranty on that particular part for 5 years/60k miles.

I took the letter to the Ford dealer and asked them to check it out. They tell me it was code P0401, and that the DPFE sensor can cause that particular code.

They replaced the DPFE sensor and cleared the DTC, and I haven't had any problems with it since. Luckily for me, it was covered under warranty.

It's a fairly inexpensive and easy part to replace yourself though.

 

I had the same problem on my 02. I just replaced the DPFE sensor and it fixed the problem. It's around $30 from the dealership and takes about 2 minutes to replace (literally). There are no screws and its right on top of the engine.

 

Thanks alot.

 

A P0401 that comes into a dealership AUTOMATICALLY gets a new DPFE sensor. Ford recognizes that their old sensors are THAT bad.

If the P0401 code comes back on KOER testing, theny thy actually do some diagnostic work.

Steve

 

Do i have to go to the dealership to get this sensor or can i go to a parts store to get this? I get the code P0401 but its closer to go to the parts store than to the dealership

 

Parts stores should have them I would think. Maybe you could order one from a ford parts website?

 

Parts stores should have them, but for some reason I was told to stick with the Ford sensor. I don't remember the reason, but something about the sensor being updated. I'm not completely sure about this, but it maybe worth looking it (or it may not).

 

Replace your DPFE sensor and while you are there check the hoses going to the sensor and make sure there not split or plugged up if they are replace them also. Stay with the ford sensor they have been completely updated. Ford used to use a certian electronics company and went to another after endless failures of quality control checks of elect. parts. One of them being the DPFE.

 

Hey guys, so I have no clue about engines, but I have the same problem, I was told from Autozone to buy and install the EGR Sensor valve, is that the same thing as the DPFE?? I have the same problem with service engine light and the insuffencent air flow code. Oh BTW its for a 2001

Thanks!!

 

Anytime a get a ford with a P0401 code i replace the DPFE first. Rarely does the EGR valve ever have a problem.

 

Your problem is going to Auto zone. Or at least it's that way where I live Ha. I use O'Reillys. But I've been having same issues with my '01 f150 5.4 L.

 

That post was made only 8 years ago........

Go ahead and get the codes from Autozone, but then post them here for proper interpretation.

 

But EGR valves do fail. There is a specific test using a hand held vacuum pump that can isolate the issue - or the EGR valve in question can be removed & directly inspected, but a vacuum source is still necessary to see the valve in action. An aftermarket EGR valve is cheaper than a OEM DPFE replacement. I have had to replace both, 2 different fault codes happened to me, 2 years in a row.
---- These 2 items are the easiest and simplest things to replace for a P0401 code, this is not to say you should always replace them first, which is also known as "throwing parts and money at a problem"

 

You don't even need a vacuum pump. With the engine idling, pull the vacuum line off the EGR and connect a length of vacuum line to it and suck on it. If nothing happens, the EGR valve is bad. If the idle gets rough and maybe even stalls, the valve is good and you probably need a DPFE or the EGR line is rotted away down at the exhaust manifold.