1997 - 2003 F-150

P0401 Error Coder. (EGR problems)

Old May 21, 2012 | 10:08 PM
  #1  
Retto4's Avatar
Thread Starter
|
Senior Member
Joined: May 2012
Posts: 110
Likes: 0
From: Augusta, Ga
P0401 Error Coder. (EGR problems)

Just checked my truck and it threw up the error P0401 which is EGR insufficient flow detected. Well I was wondering what some of the problems could be and how to fix it. If it needs fixing would it just be better to run an ERG delete? thanks.
 
Reply
Old May 21, 2012 | 10:16 PM
  #2  
jbrew's Avatar
Technical Article Contributor
Joined: Oct 2005
Posts: 25,641
Likes: 19
From: MI
Originally Posted by Retto4
Just checked my truck and it threw up the error P0401 which is EGR insufficient flow detected. Well I was wondering what some of the problems could be and how to fix it. If it needs fixing would it just be better to run an ERG delete? thanks.
No How would you do that?
 
Reply
Old May 21, 2012 | 10:19 PM
  #3  
Retto4's Avatar
Thread Starter
|
Senior Member
Joined: May 2012
Posts: 110
Likes: 0
From: Augusta, Ga
SCT offers one on there programmers
 
Reply
Old May 21, 2012 | 11:19 PM
  #4  
glc's Avatar
glc
Senior Member
15 Year Member
Veteran: Navy
Veteran: Reserves
Joined: Dec 2006
Posts: 43,542
Likes: 819
From: Joplin MO
What year and engine?

http://www.obd-codes.com/p0401
 
Reply
Old May 21, 2012 | 11:25 PM
  #5  
Bluegrass's Avatar
Senior Member
Joined: Jul 2004
Posts: 6,200
Likes: 39
From: Easton, Pa.
I don't know if your concerned with fuel mileage or emmisons but the EGR improves mileage a bit.
If you don't have a programmer, would you spent $300 +/- just to zero out the EGR function instead of repairing the problem?
Then after that the PCM is non stock. If there are other troubles that might require a reflash your back to the original program again.
If you sell the truck the next owner is up against the same possibility.
First thing is to understand what the 401 test is.
The test is to check flow rate through an orfice, measure it and tell the computer the result using the DPFE sensor.
If out of limits on the low side it is a low/no flow, setting a 401 code.
Causes are a blocked port behind the EGR, the EGR vacuum regulator, the hoses, DPFE etc.
It's all right on the outside to work on.
Even if you did a delete in program, no hardware need be altered, removed, blocked or touched in any manner..
Good luck.
 

Last edited by Bluegrass; May 21, 2012 at 11:30 PM.
Reply
Old May 22, 2012 | 08:57 PM
  #6  
aaron1998f150's Avatar
Senior Member
Joined: Jun 2010
Posts: 143
Likes: 0
no take of your egr and on the top nipple suck on it and see if it moves up some times does cloge up if not check the little vacume lines i had problems with this and it was that my vacume lines were leaking hope that helps
 
Reply
Old May 22, 2012 | 09:08 PM
  #7  
jbrew's Avatar
Technical Article Contributor
Joined: Oct 2005
Posts: 25,641
Likes: 19
From: MI
Originally Posted by aaron1998f150
no take of your egr and on the top nipple suck on it and see if it moves up some times does cloge up if not check the little vacume lines i had problems with this and it was that my vacume lines were leaking hope that helps
Sort of lol. You attach a section of hose to the valve, ie green line port. Suck on that like your drinking a milkshake. You could do it your way if you abnormally long lips, - or you plant your face into the engine compartment while it's running. THAT would be entertaining.

The two most common problems for the 4.6L, -Bluegrass mentioned them all I believe. The EGR Plenum ports are clogged, or the DPFE is bad.

If the EVR is bad, usually it will stick open and you'll constantly have vacuum at the EGR valve. The vehicle will run like crap.

Those emission lines also crack at times and a leak will cause non-flow, -insufficient.
 
Reply

Trending Topics

Old May 22, 2012 | 09:08 PM
  #8  
Retto4's Avatar
Thread Starter
|
Senior Member
Joined: May 2012
Posts: 110
Likes: 0
From: Augusta, Ga
its a 97 4.6. well i would be getting the tune for more than just the EGR delete. but thanks bluegrass, thats really helpful.
 
Reply
Old May 22, 2012 | 09:12 PM
  #9  
jbrew's Avatar
Technical Article Contributor
Joined: Oct 2005
Posts: 25,641
Likes: 19
From: MI
That was the most common, there's a few more that aren't so common.
 
Reply
Old May 22, 2012 | 09:20 PM
  #10  
jbrew's Avatar
Technical Article Contributor
Joined: Oct 2005
Posts: 25,641
Likes: 19
From: MI
Originally Posted by Retto4
its a 97 4.6. well i would be getting the tune for more than just the EGR delete. but thanks bluegrass, thats really helpful.
Just understand. This could easily be fixed without costing you a dime.

Running with or without the EGR system makes no difference at all in performance, - except you could loose your economy, -bad gas mileage.

So the question is, why would you do this knowing what you know now?
 
Reply
Old May 22, 2012 | 10:38 PM
  #11  
Retto4's Avatar
Thread Starter
|
Senior Member
Joined: May 2012
Posts: 110
Likes: 0
From: Augusta, Ga
well i didnt know this at first. I'm only 18. but now that i know, i want the best mileage i can get. so i'll just fix it.
 
Reply
Old May 22, 2012 | 10:46 PM
  #12  
jbrew's Avatar
Technical Article Contributor
Joined: Oct 2005
Posts: 25,641
Likes: 19
From: MI
Your welcome.
 
Reply
Old May 25, 2012 | 09:31 PM
  #13  
Alfredoleffew's Avatar
Member
Joined: Apr 2012
Posts: 44
Likes: 0
From: Pacoima
I had the same problem so I just took off the throttle body and eye valve then cleaned them out. It's all carbon build up. Mine was so bad that I drilled out the carbon with a drill and scrapped them really good. Lots of cleaner helps with this also. Just do it right the first time....
 
Reply
Old May 25, 2012 | 10:03 PM
  #14  
jbrew's Avatar
Technical Article Contributor
Joined: Oct 2005
Posts: 25,641
Likes: 19
From: MI
Originally Posted by Alfredoleffew
I had the same problem so I just took off the throttle body and eye valve then cleaned them out. It's all carbon build up. Mine was so bad that I drilled out the carbon with a drill and scrapped them really good. Lots of cleaner helps with this also. Just do it right the first time....
That was all ready posted, at least twice, just using the proper component name. But thanks for the support, -in fact we've been posting this fix for years lol. That's correct for the 4.6L's.
 
Reply


Thread Tools
Search this Thread

All times are GMT -4. The time now is 11:19 PM.