Just thought I would share my recent EGR valve replacement experience.

If someone is looking for tips WD-40 my friend and let that stuff sit as long as you can.

Well my service engine light came on so I pull the code and to my dismay I get P0401, no it couldn't just be a gas cap or something simple, it had to be; insufficient EGR flow. After checking the voltage and resitance of the sensor and the regulator I come to the conclusion that I need to replace the Valve Well after letting the threads soak in WD-40 for 2 nights (all the time driving my wifes car to work) I finally get the egr pipe removed from the exhaust manifold, now I can't get the stinkin valve off the egr pipe, so I soak it down with WD-40 again and let it set for the third night. To make things worse I live in an apartment complex that doesn't allow vehicle maintenance done in the parking lot so I have to wait until the manager goes on vacation or Sunday. Next day I get up after working till 3 am and comence again. This time the valve comes right off I am in the process of reinstalling the valve and egr pipe and I try to push the pipe over to drop into the manifold when the webbing in between my index finger and thumb get pinched with it. Picture this before you say "no big deal who hasn't done that before." The manifold is just behind the drivers side tire so I have my body wedged between the tire and the fender with one arm stuck I can't move my body around in order to get my other arm in to push and lift the pipe to get my hand back out, and the stupid threads have to much meat for me to just yank my hand out. 20 minutes go by before I can flag one of the apt. maintenance guys down to take the valve back off so I can get my hand back out. Ok now my hand is out and I have the egr system put back together. I clear the code by pulling the battery, I let the truck idle for a good 15 minutes to let the PCM reteach it self then I drove it for about 2 miles at a constant as possible speed. No problem, truck starts and idols fine. Acceleration is great cool problem solved.... NOT!!!! The stupid light is back on with the same code. I have never ever let someone get under the hood of my vehicle but after this experience I am really contemplating dropping her off at Midas.

Hope I could provide some... well at least some amusement.

If anyone has any ideas as to what maybe bringing this code back please do chime in. If and when I get it figured out I will post my results

 

only advice,

dont drop it off at midas. I have no idea what could be setting the code off, but dont take it to midas, more likely than not, they won't know any more than you do...unless you have a buddy who works there - just my own experience.

 

clean the erg ports on the intake. thats what cause mine to set a code. they were super clogged

 

Yea , your valves fine - P0402 is the poppet valve or diaphragm (or EGR valve) .

PO401 is dirty ports in the Plenum or DPFE sensor fault, not the valve

BTW - The EGR pipe disconnects on the valve itself. Trying to loosen @ the manifold is asking for trouble and isn't necessary. Man, what a bunch work and trouble you went thru for nothing. If the EGR Pipe nut is froze onto the valve - You just crack it loose while the trucks running when fully warm.

If the EGR valve was in question (which it was not), all you have to do to test is pull the hose off and stick a scrap piece of hose in it's place. while the truck is running , suck on the scrap piece of hose as if you were drinking a milk shake. If your your idle deflects and engine almost stalls / the valve is operating a it should.

You should have came here first - This has been talked about many times on this site, the search bar is an awesome feature. Here , I'll search it for you ~ Typed "PO401" =

https://www.f150online.com/forums/se...archid=1774844

JACKPOT!

 

Thanks for your opinion but I checked the ports and the sensor before attempting to remove the egr valve from the egr pipe.

I have a feeling the clog is in the egr pipe orifice (located in the egr pipe in between the two hoses that go out to the sensor).

I really don't feel like taking the stupid thing back apart so it will just have to wait for now.

 

If the ports are clean / replace the DPFE Sensor . Voltage don't matter - The DPFE is sending incorrect data to the PCM. I seriously doubt the orifice is plugged ... That just doesn't happen unless the vehicle sits for long periods of time. The EGR metering Orifice + tube requires no maintenance and is ironwork only. However, in order for the device to function correctly it must be gas tight both at the exhaust and the inlet ends. If leaking , it's posible to generate the 401.


When(if) you replace the DPFE - Get that sensor at dealership / they have been updated within the last year and many third party suppliers do not have the updated sensors.

Theres been many who have replaced this sensor from other suppliers that have failed either right away or shortly after install.

Leave that pipe alone, haven't you learned your lesson yet

 

I really don't like playing baseball with a problem but if it means I don't have to take the GD EGR pipe off again I might just do that. I took her to autozone to have the code erased with the scanner just to make sure it was really gone. If it does come back I am going to completely tear down the throttle body and clean every damn hole in it. I did notice after reading some other posts I might not have checked the ports as well as I thought (I didn't take off the little elbow thing). YeeHaw busted knuckles here we come again. Will post final results soon but right now its :30