Got this code # 0401 E.G.R. valve. I took it off and cleaned it, & checked it with vacume, it seames to check out all rite, Still had same code after a few milles. Then i replaced the senser that feeds the egr, or the positioning senser, turned off the check engine lite agin but after a few miles back on and same code , any ideas??? Thanks Gil
My truck about a year ago was doing the exact same thing throwing code P0401 - I ended up first changing the egr valve. About 2-3 days later the code came back so I cleaned the tube leading from the exhaust manifold with a long tube cleaner. 2-3 days later the code again. So I then replaced the DPFE sensor which sounds like you also changed. Still 2-3 days later the code was back on. My truck didn't run any differently so I figured it can't be too bad. I finally got my hands on the Factory Service Manual and it had the test procedure for determining what part was bad. It ended up being the vacuum selenoid that puts vacuum to open the egr valve. I changed it out and haven't had a problem since.
Silver Bullet
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1998 F150 Silver 4WD Styleside V6 Reg Cab 3.55 RE - 285/75R16 Cooper Discoverer AT's on stock rims, Extang soft cover, Rhino step bars, exposed K&N air filter with retainer ring, Steel Horse Brushguard with 2-100W KC Daylighters, Superchip, black wind deflectors, AVS headlight covers, 29" Cherry Bomb glasspack, sliding rear window.
Hi I just had the intake gaskets replaced I hope they cleaned the ports. But you say check vacum on egr, rite? So i will take hose off egr and plug it then hook my vacume pump up and see whe i put vacum on it if it stalls or dies rite?? Thank,s I will try it as soon as it stops rainning hear.
yea you can use a vacuum pump if you want. i just suck on the end of the hose and it will quickly start stubbling and stalling if its working.
if it doesnt stumble or die the ports are either clogged or the egr valve is bad. you might be able to get a finger under it and feel the diaphram moving but do this when the engine is cold egrs get real hot.
did you replace the sensor with the 2 vacuum lines and an electrical connector on it? thats the dpfe sensor which is ussually the cause for that code they just get stuck sometimes.
and what year is it on?
oh i assume its a 97 if you did intakes. this means you would most likly have the aluminum dpfe sensor replace it with the new redesigned plastic one.
Last edited by Mr_Bentwrench; 04-13-2004 at 03:31 AM.
Yes that is the peice i replaced, my old one was aluminum, this new one is black plastic , i got it at advance auto parts, would i have to have the intake pulled back off to clean these ports?? When this first started i was just getting a code for miss fire on 1 & 4 and i was lossing antifreze, in those 2 cyl. i didnt start getting this code till after i had this work done. I went ahead and had head gaskets replaced,& valve job done on heads, the truck seems to run alwrite, just dont like this lite on. thank you for all your help. the rain is supposed to end here wendsday so i will check the vacume tomarow with any luck. Im on oxy. & use a whell chair , so you can see why it takes me awile to do thangs. poor people got poooooor ways. thanks Gil
Well I finally got it checked , It started to die as soon as vacume was applied to the egr, I had the vacume tube pluged, Then i checked for vacume comming to it, nothing at idel, thats about 6 or 7 hundered rpm, then when i speed up RPM to about 15 to 16 hundered RPM it goes up to about 5 or 6 inches of vacume, any ideas?? Thanks Gil.
i've deleted the causes that we've already tested. is there a chance you hooked the hoses up backwards? or maybe one slipped off of the sensor?
the 2 top ones *EGR valve we have kind of tested but could still be causeing a problem.
i would check the rubber hoses and the metal egr tube to make sure everything is hooked up. the tube runs from the egr valve to the right side exhaust manifold.
to really diagnose this we would have to get into "pid" values with a scan tool. also check the electrical connector to see if any pins pushed out or wires are damaged.
Thank You Mr-Bentwrench For working with me on this. I checked the tube out its hooked up. and the vacume hoses are on rite, i will check the wires tomarow, when i put the new senor on and reset the light , it came back on in about the same amont of time before i changed it, so i dont thank it was in the sensor itself, I am going to look real close to see if wires or somthing could have been damaged when i had it worked on by accident, I realy hate to take it to Ford dealer, Those hourly rates kill me. Thanks Gill OH! what is (pid) vales mean ??
its what the scan tool shows for sensor values like voltages and frequancies for different sensors that the pcm monitors. P parameter I identification WOW i cant remember what the D stands for. hmmm maybe its stands for Data.
you can compare these values to help find which sensor is not working right or to verify that the wiring is good and even use them to diagnose lean and rich conditions caused by vacuum leaks and lots of other things.
you can use a volt meter to get these values sometimes too but it gets tricky and if you read something wrong its easy to get thrown off course.
one way to test the wiring is to unplug the dpfe sensor i think this would send it to 5 volts and throw code p0402 excessive egr flow. i might have it backwards though that might be if you have code p0402 first the you unplug and see if you get a p0401 i will check into this when i get a chance no time right now.
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.
O.K. I checked volts , From the top of the plug down, I got 5.02 volts , Middle 0.01 , And bottom 5.04 volts, I hope this makes since to you, If you can thank of anythang next please let me no Thanks Gil.
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.
Last edited by wizkid1358; 02-19-2009 at 11:12 PM.
Reason: bad grammar
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Code # 0401
. 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.
Linear Mode
