Code # 0401
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Joined: Mar 2009
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Questions regarding this test
Disconnect D.P.F. EGR sensor.
Key on, engine off.
Measure voltage between the sensor VREF circuit and SIG RTN circuit at the D.P.F. EGR sensor vehicle harness connector.
Is VREF voltage between 4.0 and 6.0 volts?
if the connector has these values when unplugged from dpfe sensor the dpfe sensor is bad.
which would be the same as unplugging sensor and seeing if code P0402 excess flow it tripped.
Key on, engine off.
Measure voltage between the sensor VREF circuit and SIG RTN circuit at the D.P.F. EGR sensor vehicle harness connector.
Is VREF voltage between 4.0 and 6.0 volts?
if the connector has these values when unplugged from dpfe sensor the dpfe sensor is bad.
which would be the same as unplugging sensor and seeing if code P0402 excess flow it tripped.
Thank you for your help?
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Joined: Feb 2009
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From: lowell indiana
I would go to the parts store and get new gaskets for the throttle body and intake adapter and see if the egr ports are clogged or not. This may save you alot of headaches and money. Just because the voltage isn't changing doesn't mean the sensor is bad, it may just mean it is not sensing anything different because the ports are completely clogged with carbon.
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Joined: Nov 2007
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more dpfe fun
I replaced my dpfe 1.5 years ago from kragen (they had one) instead of ford (didn't have one) in order to pass smog. It worked, but on my trip out to PA the last four days, it has been firing the 0401 code whenever I restart the truck (except a few times when it was pretty hot). I have been waiting for the kragen version to fail, guess it waited till I would be out of california :^). Off to find a Ford dealer locally.
cheers
cheers
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Joined: Jun 2009
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From: Toronto
Thank you wizkid1358! I went to the Tomco website and read the tech tips. The plastic bodied and metal bodied DPFEs both have linear outputs, but they have different slopes. The plastic one produces 1 volt at 0 pressure difference, while the metal one produces less than 0.5 volt for the same difference. When the computer compares the voltage output to it's stored expected value at a given pressure difference, it won't match and an "insufficient EGR flow" code results. So a vehicle that originally had a metal one should get a metal one as a replacement.
Last edited by RONinTORONTO; Jun 5, 2009 at 05:58 PM.
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Joined: Jun 2009
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From: Toronto
I know this is an old thread, but if your truck has an aluminum sensor, only use the Aluminum one (Tomco or motorcraft). The new plastic ones may appear better but they use different technology and put out a different signal voltage which is lower than the good ones which will cause the code to come up again. For me I bought the truck used ('97 f150 4x4 4.6L VIN code 6) and it came with the plastic sensor and had the EGR insufficient code, so I went Autozone and bought the sensor but still had the code. I have now completely replaced the EGR system (EVR, EGR Valve, tube, vacuum line, and hoses going to the sensor) and still have the code. Bought the Tomco 10906 and that solved the problem.
. The new plastic ones may appear better but they use different technology and put out a different signal voltage which is lower than the good ones which will cause the code to come up again. For me I bought the truck used ('97 f150 4x4 4.6L VIN code 6) and it came with the plastic sensor and had the EGR insufficient code, so I went Autozone and bought the sensor but still had the code. I have now completely replaced the EGR system (EVR, EGR Valve, tube, vacuum line, and hoses going to the sensor) and still have the code. Bought the Tomco 10906 and that solved the problem.
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Joined: Apr 2011
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My 99 4.2 has the metal EGR differential pressure sensor.
Is it the prevailing wisdom still that I need to replace with a metal one?
I keep getting code P0401.
Tube and intake passages are clear.
EGR works.
Sensors all test within limits according to the Haynes manual.
Many posts on this board indicated that the dpfe is the most likely culprit if everything tests OK.
Found one on ebay here: http://www.ebay.com/itm/400619453567...84.m1423.l2649
It is obviously not metal.
Does it really make a difference?
Is it the prevailing wisdom still that I need to replace with a metal one?
I keep getting code P0401.
Tube and intake passages are clear.
EGR works.
Sensors all test within limits according to the Haynes manual.
Many posts on this board indicated that the dpfe is the most likely culprit if everything tests OK.
Found one on ebay here: http://www.ebay.com/itm/400619453567...84.m1423.l2649
It is obviously not metal.
Does it really make a difference?
Last edited by LynnBilodeau; May 11, 2014 at 06:57 PM.
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Joined: Apr 2011
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Anyone replaced this part lately? If so, with what brand?
Did your SES light stay out?
I just don't want to buy an aftermarket one if it isn't going to work properly.
I am fine buying a Motorcraft part. There is one on ebay:
http://www.ebay.com/itm/131102294919...84.m1423.l2649
I see them listed as DPFE-4 and DPFE-5 but both ads say they fit my 99 F150 with the 4.2. Anyone know the difference, if any?
Thanks in advance for any help.
Did your SES light stay out?
I just don't want to buy an aftermarket one if it isn't going to work properly.
I am fine buying a Motorcraft part. There is one on ebay:
http://www.ebay.com/itm/131102294919...84.m1423.l2649
I see them listed as DPFE-4 and DPFE-5 but both ads say they fit my 99 F150 with the 4.2. Anyone know the difference, if any?
Thanks in advance for any help.