I take some of the blame for those hits, because you just summarized my experience: P1401, fixed with a Motorcraft-made DPFE, shortly after followed by a P0401 with what turned out to be a totally clogged EGR.

 

where the dphe sensor hoses connect to the egr tube will clog up in the orfice thats built in the tube, had to replace my tube after going through all the other trouble shooting, havnt had the code pop up since

 

This cracks me up...a thread that I replied to nearly nine years ago simply won't die!

 

Well the reason is a lot of owners will keep having an issue with the EGR system and will not do any research and understand the facts that have already been presented.
Another reason for some, is the search feature is to rough to get to the things they want to know when they don't know what their looking for.
To easy to keep asking over and over wanting to be told the exact fix without any effort.
It dosn't work that way very well for many people.
If they have no background to understand , no tools etc, it's a lost cause.

 

1997 Exp
V-8

So, my CEL came on, but it doesnt stay on. The code says: Exhaust Gas Recirculation Flow Excessive Detected

From researching here; I do think it is EGR related. BUT, I don't want to just replace the DPFE Sensor because my CEL is not staying on.

Maybe just the hoses that lead to it?
Anyone else have these get gunked up and need replacing?
I also read that if you buy the cheap DPFE Sensor; it will most likely fail again. So, I actually bought it from a Stealer, and they said I can return it unopened no problem.

Any thoughts?

Thanks!
Mike Newman

 

Mike.
Excess flow is a 402 code.
You need to know more about the system it refers to or you just guess.
The EGR could be leaking, the EVR third port could be plugged or solenoid slow to close, the DPFE slow to respond or a hose hard and cracked or disconnected.
Without a check out to find the fault cause you will have to put up with the CEL.
Just reading the simple short code discription without the background behind it leaves you high and dry.
.
The PCM does a test of the EGR system for a number of functions by setting up test conditions then reading the results from the DPFE sensor.
.
Start by removing the EVR solenoid and cleaning the filter under the round cap and be sure the inside of the valve is free to move by spray cleaning it.
Inspect the hoses on the DPFE, the EGR to EVR etc.
Once you begin to eliminate possible causes there are only a few items left.
Good luck.

 

I recently purchased a 1999 F250SD w/ V-10. It appears that the engine was swapped out. The service engine soon light is on and the code pertains to DPFE. I bought a new one but when I went to replace it, found that there are no wires connected to the DPFE sensor. It's there, but disconnected...with no wire connector anywhere to be found. The truck runs really nice. The Ford mechanic is stumped. I'm stumped. Was the wiring harness swapped? Should I keep spending money to solve this issue or can the truck function without the DPFE connection hooked up? The truck did pass emissions.

Thanks for your thoughts.

 

The motor will run without the EGR function.
As long as the code is set the PCM will not try to use it.
Why is there an EGR system?
1. To reduce NOX emissions.
2. Mandated by the federal EPA as a method of NOX reduction.
3. When in operation it reduces combustion temperature to reduce NOX.
How does it work?
1. PCM commands the system at a certain programmed speed, RPM and TPS output in a timed period, to a decision to activate it.
2. Activation, cuts back fuel and advances igniting timing to make the operation transparent to the driver. This normally improves fuel mileage to some degree.
Some troubles the system causes.
1. At the very lean conditions it creates, a faulty coil can cause a misfire or stumble.
2. Reduced fuel mileage if the system is inhibited.
3. A leaking vacuum control solenoid can hold the EGR open or cause it to be slow in closing. This can cause rough idle and running.
.
The diagnostic tests the system does detects flow when it should not be, detects no flow when there should be, detects connecting hose issues.
Other trouble with the system takes understanding all this to be successful or some luck at replacing parts.
The DPFE is just a 'reporting' sensor and does not control any function.
Look up the code definitions to see what part of the function fails.
A 401 code is a 'low' flow.
A1401 is an electrical connection issue with the DPFE.
The two are not the same.
.
And you all thought the EGR system was simple!
Good luck.

 

I sure appreciate that Bluegrass. Thanks a million.

 

I quit thinking that way years ago.

 

What an interesting thread! I'm a recent F150 owner (first truck ever, I love it), 1999 F150 XLT 4.6L Triton 2WD. I'm also a beginner DIY'er (at 39) because I can't afford garage labor anymore.

Anyway, long story short, my F150 was showing like 6 codes, all tranny related, I changed filter & fluid, cleaned magnet, etc...all codes gone now when I hook up my ODBII scanner...only now I'm getting just one: P0401.

My truck is not running roughly at all. Steady idle, decent acceleration...mileage may be a bit worse though that could just be my continued fuel shock coming from a 4 cy. Accord...

Yesterday before work, I took the wiring harness off of the DPFE sensor with Key on/engine off, with neg in middle i checked both live contacts with my multimeter and they read steady 5v...can I assume it's not an electrical issue? Or do I need to do manual vacuum test to see if there's voltage fluctuation?

So then check EGR valve...tubes...then move to DPFE sensor...clean throttle body ports too, first?

 

The 401 code is set after the PCM detects the signal from the DPFE as out of limits.
Your next test is to open the EGR while the motor is at running idle.
Do this with a vacuum pump attached in place of the EVR hose.
.
Observe the result on idle quality.
.
If no difference, the port behind the EGR is your problem. It's plugged with carbon or (very seldom) the EGR does not open with vacuum applied as would be shown on the vac pump gage.
.
If idle gets rough, the port and EGR are open and ok.
The conclusion would be the DPFE sensor is not reporting the result of the PCM test of the system, properly.
Good luck.

 

Thank you, Bluegrass. I have a vacuum pump on Amazon I want but it's still about two weeks out as far as purchasing...I'm getting all my AC stuff, manifold gauges, pump, compressor, thermometer, etc...I finally realized just how much I'll save if I start doing basic car stuff myself. I just finished changing the fuel pump on my 92 accord which entailed dropping the tank...that was fun in South Florida on a blacktop driveway with no creeper or shade in 98 degrees and 1000% humidity, lol...

 

After repairing several leaks in the vacuum lines for the EGR system, cleaning out the EGR valve and plenum, and changing the DPFE, my 99 F150 Lariat 4x4 5.4l Flareside is now reporting a P1401. If you don't know what the code means, for Ford it's "input voltage to DPFE sensor too high" according to Torque, which is an awesome app for Android that uses my Bluetooth OBD2 adapter and my phone. I did not spend too much on the sensor by going NON-OEM, and I think maybe I should've gotten a Ford part. Is there any other cause that would create a p1401? The voltage supplied comes from the PCM, and should not exceed 4.9V?

 

A 'high' means the PCM detected the voltage as too high or there is no 'load' from the sensor on the circuit to the PCM.
The way the PCM knows this is a current sense in the PCM. It monitors a small drop across a resistance to tell what the current is..
It is either within limits, too low or too high and sets the matching code per the condition detected.
Is it the harness, connector or the DPFE sensor internally?
.
Note the 1401 is an electrical code not an EGR performance system failure code.
Good luck.