code po401 help

Reply Subscribe

Thread Tools

Search this Thread

Apr 1, 2013 | 09:34 PM

Richard.Parker

Thread Starter

Junior User

Joined: Feb 2013

Posts: 50

Likes: 0

code po401 help

So I have a 1999 ford f 150 4x4 with the triton 4.6. I have worked around all day on this truck trying to fix different things on it. I am getting this code which is to little flow on the egr system. So I take the egr valve off and cleaned it and tested the diaphram inside and it moves freely with no problems. I reset the codes by taking the positive side off the battery and took it for a drive and after a few miles it came on again. So I got the same code again when checked and i bought a new dpfe sensor and changed it out. Drove it again after reseting codes and after a few miles it was right back on. I havent had it checked again to see if its the same code but im suspecting it is. I have not took the throttle body off and checked the egr ports to see if they are blocked. Is there anything else that c ould be causing it to read that same code over and over?

Apr 2, 2013 | 07:52 AM

Bluegrass 7

Lead Driver

Joined: Sep 2006

Posts: 7,907

Likes: 143

It's easy to tell if the passage is blocked by applying Vac to ther EGR while the motor is idleing.
If the motor begins to stumble the passage is open.
Good luck.

Apr 2, 2013 | 11:51 AM

Richard.Parker

Thread Starter

Junior User

Joined: Feb 2013

Posts: 50

Likes: 0

Quote:

Originally Posted by Bluegrass 7

It's easy to tell if the passage is blocked by applying Vac to ther EGR while the motor is idleing.
If the motor begins to stumble the passage is open.
Good luck.

I applied vac to the egr valve just like you said the engine stumbled. so i assume the egr ports are open. what else could cause it?

Apr 2, 2013 | 03:39 PM

Bluegrass 7

Lead Driver

Joined: Sep 2006

Posts: 7,907

Likes: 143

Only item left is the DPFE.
Good luck.

Apr 2, 2013 | 04:07 PM

Richard.Parker

Thread Starter

Junior User

Joined: Feb 2013

Posts: 50

Likes: 0

Quote:

Originally Posted by Bluegrass 7

Only item left is the DPFE.
Good luck.

I already put a new dpfe on it yesterday and unhooked battery to reset computer and when the light came on i had codes read again and it was showing the same code and also the codes for the abs and wheel sensors and i put new abs sensor in rearend and the abs light has not come back on. i sprayed starting fluid all over the motor and vacuum lines hoping to detect a leak but no luck. i even went ahead and took off throttle body today and cleaned the ports and i have reset computer again so i will see if it comes back on. if it does then im stuck other than maybe a vacuum solenoid.

Apr 2, 2013 | 04:55 PM

SteevenH

Senior User

Joined: Aug 2009

Posts: 304

Likes: 2

DPFE Sensor probably. Check this web site out , it might help.

Part 1 -How to Test the Ford EGR Valve and DPFE Sensor.

Apr 2, 2013 | 08:14 PM

Richard.Parker

Thread Starter

Junior User

Joined: Feb 2013

Posts: 50

Likes: 0

I may have found my problem. i had the hoses that go to the dpfe to the tube crossed. i hope thats it anyway plus i went ahead and got a new dpfe so i have my fingers crossed