Ford Ranger Forum - Forums for Ford Ranger enthusiasts!

Go Back   Ford Ranger Forum - Forums for Ford Ranger enthusiasts! > Ford Ranger Technical > General Tech
Forgot Password? Join Us!


Reply
 
LinkBack Thread Tools Search this Thread

  #1  
Old 06-15-2012, 05:16 AM
Learning to use the forums
 
Join Date: Jun 2012
Posts: 6
Angry EGR Flow Insufficient (PO401)

I have a 1999 Ford Ranger 2.5L Ext cab, 5-speed manual. I've been battling this stupid code forever now, and it looks like I'm not alone. Here is what I have already done:

* Replaced the DPFE sensor (in retrospect, I probably didn't need to, but that's what the part store said the greatest change of failure was so...)

* Replaced the EGR vacuum solenoid - One of the lugs on it was cracked, so obviously no vacuum would get up to the EGR valve itself;

* Replaced / repaired vacuum lines - A couple of them were worn / had cracks, and vacuum as intermittent;

* I placed a vacuum gauge directly on the EGR valve at idle, as I pumped vacuum, the engine hesitated and eventually stalled, which would seem to indicate that the EGR valve itself DOES in fact work-- Apply vacuum, it opens, and the exhasut gas enters the manifold. The green vacuum line coming up to the EGR valve from the solenoid has a "slight" puff of pulsating vacuum on it at idle. I take this to indicate that the solenoid is closed (as it shoudl be at idle), but does indicate that vacuum is present on it;

* I pulled the boot from the EGR solenoid and confirmed that there is good vacuum on the red line that supplies vacuum pressure to the solenoid;

* When I rev the engine throttle, even if I hold it up around 4,000 RPMs or so for a bit, the EGR solenoid doesn't seem to be opening (I removed the green vacuum line from the EGR valve and held it to see if vacuum ever came onto it as I opened the throttle.

I really hate replacing $80+ parts with no good reason. Obviously the two major components in this system that I have replaced I have no reason to beleive aren't working fine, and the EGR valve itself I was able to test it for functionality, so I don't think the lines are clogged. It would seem to me that the issue here is that for some reason, the EGR solenoid is not being told by the ECM to open the EGR valve-- Valve never opens, no EGR flow, hence the code. Any suggestions on how I can tell the ECM to energize the solenoid, to confirm its functionality, or some other way to evaluate and test this? Thanks!

-- James
Reply With Quote
  #2  
Old 06-15-2012, 07:31 PM
Learning to use the forums
 
Join Date: Jun 2012
Posts: 10
Default Re: EGR Flow Insufficient (PO401)

I'm assuming you checked for carbon deposits in the barbs for the hoses connecting the DPFE to the EGR tube. Check continuity between the the wires between the computer and the DPFE and also between the computer and EGR solenoid. Make sure the pins in the connectors are good and tight too.

(TO YOUR QUESTION ON TESTING)

If that is okay then you would have to hook up a volt meter to the EGR solenoid to verify that the computer is commanding the EGR to open (and what voltages to look for I have no idea best guess is 5 volts D.C.) and to verify that that it is opening we would need to tee in a vacuum gauge at the egr valve to verify proper operation of the solenoid while driving. (This is the best way to run the test.)

So if our wires are okay, flow to the DPFE is good and, the computer is commanding the EGR sol to open the valve and vacuum is getting to the EGR valve, that leads us to two conclusions.

1. Aftermarket DPFE is bad, install factory part. DPFE's are always bad with a P0401.
2. PCM is bad and isn't reading what the DPFE is telling it.

If still unsure/don't want to do all that work take it to a dealership. It will take them about 30 minuets to figure it out with the IDS scan tool.

Hope this helps.
__________________
97 extended cab 4.0 5 speed 4x4 31 M/T warn manual lockers where it matters. Fancy black euro tail lights and a nice stereo for fun.
Reply With Quote
  #3  
Old 06-21-2012, 07:15 PM
Sept. TOTM
 
Join Date: Jul 2011
Posts: 11,370
Default Re: EGR Flow Insufficient (PO401)

Hey I am getting the same CEL code.

First it was a P0402 egr excessive
Now I have gotten P0401 egr insufficient 3 times now.

Let me know what u do/did to solve your issue.

I am having trouble even locating the DPFE thing.
__________________
1999 Ranger 3.0FFV-ExtCab-4x4-My 99 Build
1998 Ranger 3.0-ExtCab-4x4-PROJECT TRUCK-My 98 Build

GC-EXTREME GRAPHICS
NEED CUSTOM DECALS, APPAREL, or GLASS MUGS?
Visit My Thread!
Custom Stuff, Great Quality, & Great Prices!
These Graphics ROCK!

Buggman LEDS & GC-Extreme Graphics Joint Venture Mod Products Coming Soon!
Are you READY?!
Reply With Quote
  #4  
Old 06-21-2012, 07:20 PM
Cant kill a ranger
 
Join Date: Mar 2011
Posts: 674
Default

Quote:
Originally Posted by gcextreme
Hey I am getting the same CEL code.

First it was a P0402 egr excessive
Now I have gotten P0401 egr insufficient 3 times now.

Let me know what u do/did to solve your issue.

I am having trouble even locating the DPFE thing.
Has two vacuum lines coming from it next to a computer plug in. The two lines run to the egr tubing

Sent from my iPhone
__________________
99 xlt supercab xlt 4.0l ohv 4x4
mirror tint all around
2 piaa 580 lights and 2 220w dick cepek lights
100w pa system
2"front/1.5 rear lift
1 10" pioneer champion sub/ 1800w jl amp/ kenwood HU
31x10.5x15 Pegasus A/T
Reply With Quote
  #5  
Old 06-21-2012, 07:39 PM
Sept. TOTM
 
Join Date: Jul 2011
Posts: 11,370
Default Re: EGR Flow Insufficient (PO401)

Quote:
Originally Posted by 99Rangerxlt View Post
Has two vacuum lines coming from it next to a computer plug in. The two lines run to the egr tubing

Sent from my iPhone
Yeah... i think i found it.... its facing the front of the truck, on top of the manifold, it has a connector and to the left of it is two hoses, but they aren't side by side, left to right, they are one in front of the other....

where can i get a dpfe sensor other than the stealership.....??
hope they aren't too expensive.
__________________
1999 Ranger 3.0FFV-ExtCab-4x4-My 99 Build
1998 Ranger 3.0-ExtCab-4x4-PROJECT TRUCK-My 98 Build

GC-EXTREME GRAPHICS
NEED CUSTOM DECALS, APPAREL, or GLASS MUGS?
Visit My Thread!
Custom Stuff, Great Quality, & Great Prices!
These Graphics ROCK!

Buggman LEDS & GC-Extreme Graphics Joint Venture Mod Products Coming Soon!
Are you READY?!
Reply With Quote
  #6  
Old 06-21-2012, 07:58 PM
Cant kill a ranger
 
Join Date: Mar 2011
Posts: 674
Default

Quote:
Originally Posted by gcextreme

Yeah... i think i found it.... its facing the front of the truck, on top of the manifold, it has a connector and to the left of it is two hoses, but they aren't side by side, left to right, they are one in front of the other....

where can i get a dpfe sensor other than the stealership.....??
hope they aren't too expensive.
Bingo. Rock auto.com or a junkyard. Or.. A autoparts store one
$65 at autozone to be exact

Sent from my iPhone
__________________
99 xlt supercab xlt 4.0l ohv 4x4
mirror tint all around
2 piaa 580 lights and 2 220w dick cepek lights
100w pa system
2"front/1.5 rear lift
1 10" pioneer champion sub/ 1800w jl amp/ kenwood HU
31x10.5x15 Pegasus A/T

Last edited by 99Rangerxlt; 06-21-2012 at 08:01 PM.
Reply With Quote
  #7  
Old 06-21-2012, 08:03 PM
Sept. TOTM
 
Join Date: Jul 2011
Posts: 11,370
Default Re: EGR Flow Insufficient (PO401)

Quote:
Originally Posted by 99Rangerxlt View Post
Bingo. Rock auto.com or a junkyard. Or.. A autoparts store one
$65 at autozone to be exact

Sent from my iPhone
Ok cool.... i wonder if my 98 ranger project truck has the same one???? I could swap that and see if that helps...before rushing off and dropping $65 for a new one right now.

I will have to look at the one on my 98, to see if its the same as my 99.
__________________
1999 Ranger 3.0FFV-ExtCab-4x4-My 99 Build
1998 Ranger 3.0-ExtCab-4x4-PROJECT TRUCK-My 98 Build

GC-EXTREME GRAPHICS
NEED CUSTOM DECALS, APPAREL, or GLASS MUGS?
Visit My Thread!
Custom Stuff, Great Quality, & Great Prices!
These Graphics ROCK!

Buggman LEDS & GC-Extreme Graphics Joint Venture Mod Products Coming Soon!
Are you READY?!
Reply With Quote
  #8  
Old 06-21-2012, 08:04 PM
Cant kill a ranger
 
Join Date: Mar 2011
Posts: 674
Default

Should be the same if I remember right

Sent from my iPhone
__________________
99 xlt supercab xlt 4.0l ohv 4x4
mirror tint all around
2 piaa 580 lights and 2 220w dick cepek lights
100w pa system
2"front/1.5 rear lift
1 10" pioneer champion sub/ 1800w jl amp/ kenwood HU
31x10.5x15 Pegasus A/T
Reply With Quote
  #9  
Old 06-21-2012, 08:07 PM
Sept. TOTM
 
Join Date: Jul 2011
Posts: 11,370
Default Re: EGR Flow Insufficient (PO401)

yeah whats weird is, the truck has been running fine as far as i can tell... but one day i got a 402 excessive flow, then now i am getting several 401 insufficient flow..... i keep clearing it with my Flashpaq, but it comes back every day or so. Can i check this in the data logging section of my flashpaq? I know i can view and monitor air intake, mass air flow, and etc.. but i cant seem to find anything with the DPFE or EGR.
__________________
1999 Ranger 3.0FFV-ExtCab-4x4-My 99 Build
1998 Ranger 3.0-ExtCab-4x4-PROJECT TRUCK-My 98 Build

GC-EXTREME GRAPHICS
NEED CUSTOM DECALS, APPAREL, or GLASS MUGS?
Visit My Thread!
Custom Stuff, Great Quality, & Great Prices!
These Graphics ROCK!

Buggman LEDS & GC-Extreme Graphics Joint Venture Mod Products Coming Soon!
Are you READY?!
Reply With Quote
  #10  
Old 06-21-2012, 08:14 PM
Cant kill a ranger
 
Join Date: Mar 2011
Posts: 674
Default

Quote:
Originally Posted by gcextreme
yeah whats weird is, the truck has been running fine as far as i can tell... but one day i got a 402 excessive flow, then now i am getting several 401 insufficient flow..... i keep clearing it with my Flashpaq, but it comes back every day or so. Can i check this in the data logging section of my flashpaq? I know i can view and monitor air intake, mass air flow, and etc.. but i cant seem to find anything with the DPFE or EGR.
No, you can't monitor egr flow with the flashpaq. But check all the lines on the egr tube and egr. My friend has a 98 3.0 and the vacuum line directly on top the egr burned and had a hole in it, making the egr shut and freaked the sensor out

Sent from my iPhone
__________________
99 xlt supercab xlt 4.0l ohv 4x4
mirror tint all around
2 piaa 580 lights and 2 220w dick cepek lights
100w pa system
2"front/1.5 rear lift
1 10" pioneer champion sub/ 1800w jl amp/ kenwood HU
31x10.5x15 Pegasus A/T
Reply With Quote
  #11  
Old 06-21-2012, 08:17 PM
Sept. TOTM
 
Join Date: Jul 2011
Posts: 11,370
Default Re: EGR Flow Insufficient (PO401)

Quote:
Originally Posted by 99Rangerxlt View Post
No, you can't monitor egr flow with the flashpaq. But check all the lines on the egr tube and egr. My friend has a 98 3.0 and the vacuum line directly on top the egr burned and had a hole in it, making the egr shut and freaked the sensor out

Sent from my iPhone
Thanks.. i will look into this more this weekend.....
I appreciate the help...


what is the long term damage of like not doing anything??? Like i said, as far as i can tell its running fine......yes i do want to get it fixed... but it may not be done ASAP... i have a vacation planned, taking a motorcycle trip, and i have to spend the weekend putting my bike together, had to pull the motor to replace the stator... eww.. lots of work.. now i just gotta put the new stator in and put it all back together and make sure it runs great before my trip...
__________________
1999 Ranger 3.0FFV-ExtCab-4x4-My 99 Build
1998 Ranger 3.0-ExtCab-4x4-PROJECT TRUCK-My 98 Build

GC-EXTREME GRAPHICS
NEED CUSTOM DECALS, APPAREL, or GLASS MUGS?
Visit My Thread!
Custom Stuff, Great Quality, & Great Prices!
These Graphics ROCK!

Buggman LEDS & GC-Extreme Graphics Joint Venture Mod Products Coming Soon!
Are you READY?!
Reply With Quote
  #12  
Old 06-21-2012, 08:23 PM
Cant kill a ranger
 
Join Date: Mar 2011
Posts: 674
Default

No problem, well my friend still hasn't fixed his in about 6ish months. But, as far as I know, the egr is just emissions. Not saying you should run it a bunch with it f'd up but he hasn't had a problem

Sent from my iPhone
__________________
99 xlt supercab xlt 4.0l ohv 4x4
mirror tint all around
2 piaa 580 lights and 2 220w dick cepek lights
100w pa system
2"front/1.5 rear lift
1 10" pioneer champion sub/ 1800w jl amp/ kenwood HU
31x10.5x15 Pegasus A/T
Reply With Quote
  #13  
Old 06-21-2012, 08:27 PM
Sept. TOTM
 
Join Date: Jul 2011
Posts: 11,370
Default Re: EGR Flow Insufficient (PO401)

ok good to know... i just dont want to damage my new engine... i only have about 56K on my re-manufactured engine, and about 10k on my rebuilt transmission.

I will look at the hoses saturday, and if have time i will swap the dpfes from my 98.
Otherwise i will have to wait til after my vacation to buy a new dpfe or egr.
__________________
1999 Ranger 3.0FFV-ExtCab-4x4-My 99 Build
1998 Ranger 3.0-ExtCab-4x4-PROJECT TRUCK-My 98 Build

GC-EXTREME GRAPHICS
NEED CUSTOM DECALS, APPAREL, or GLASS MUGS?
Visit My Thread!
Custom Stuff, Great Quality, & Great Prices!
These Graphics ROCK!

Buggman LEDS & GC-Extreme Graphics Joint Venture Mod Products Coming Soon!
Are you READY?!
Reply With Quote
  #14  
Old 06-21-2012, 08:39 PM
Cant kill a ranger
 
Join Date: Mar 2011
Posts: 674
Default

I wouldnt consider it a priority unless you strive to lower your emissions haha

Sent from my iPhone
__________________
99 xlt supercab xlt 4.0l ohv 4x4
mirror tint all around
2 piaa 580 lights and 2 220w dick cepek lights
100w pa system
2"front/1.5 rear lift
1 10" pioneer champion sub/ 1800w jl amp/ kenwood HU
31x10.5x15 Pegasus A/T
Reply With Quote
  #15  
Old 06-21-2012, 10:03 PM
Learning to use the forums
 
Join Date: Jun 2012
Posts: 6
Default Re: EGR Flow Insufficient (PO401)

FWIW... I have heard that the purpose of the EGR is to lower the temperature of the combustion chamber in order to reduce emissions... and that when it's not working, the higher temperature of the exhaust gas "can" hurt your catalytic converter... Of course, that was told to me by someone at a shop with a vested interest in me having them work on my truck, so who knows.

FYI... On the DPFE sensor location... There are three parts (that I know of) to the EGR system. The EGR valve itself is up on top of the monifold... Looks like the saucer section of the Starship Enterprise w/ a vacuum line (green) going into the center of it. It is opened by the EGR solenoid, which is located on the left side of the motor (as you're facting the truck), just behind and below the coil packs. The solenoid has an electronic connector that tells it when to open. There is a little double boot on it with a red vacuum line that comes down from the manifold, and the green vacuum line that comes out and supplies vacuum to the EGR value when the computer tells the solenoid to open the EGR valve. Finally the DPFE sensor on the left of the motor, mounted to a bracket right by the rear spark plug, so it's just in front of the firewall, right below the blower motor the cabin heat / AC. It has an electronic connector and then two tubes... One connects down to the exhaust manifold and the other to the tube that goes into the back of the EGR valve.

and to replace the parts... They are about $80 each from Advance. The DPFE sensor was in-stock; They had to order the solenoid as a special order. There doesn't seem to be any way to test these components, which seems utterly crazy to me.

I still have not resolved my issue. I did test the EGR valve by starting up the truck and pulling the green vacuum line off of the top of the EGR valve, then putting a vacuum gauge on it, and pumping up the vacuum, which should open the EGR valve. The engine died (as it should) which indicates that the EGR functions when a vacuum is applied to it. That is saying to me that for some reason, the EGR isn't being activated like it should be. I've reved up the engine whilst under the hood, and I never sense the vacuum line being activated to open the EGR valve. I'm not 100% sure under what conditions the valve is supposed to open though, so it's hard to say if my "test" can be considered conclusive. Since I've replaced both the DPFE sensor and the soleoid, the only thing I can conclude at this point is that there is either something wrong with the ECM, or the wiring between the solenoid and the ECM is damaged. I prob. need to take mine somewhere and just cough up the $80 for the diagnostic.
Reply With Quote
Reply

Tags
egr, p0401

Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Egr insufficient flow Dougy'94 4.0 SOHC / 4.0 OHV Tech 4 06-11-2012 07:03 PM
Po401 Firefighter Ryan 4-Cylinder Tech 1 02-24-2011 10:42 AM
EGR -Insufficiant Flow TommyX51 3.0 Vulcan Tech 18 10-14-2010 04:36 PM
Check Engine excessive egr flow? Lonncarr General Tech 2 07-24-2010 07:31 AM
DTC: EGR Valve Insufficiant Flow schwen_108 Exhaust and Mufflers 2 01-23-2010 12:14 AM



Search Engine Friendly URLs by vBSEO 3.6.0 ©2011, Crawlability, Inc.