What could cause the code P0401

[BayChaser]

Hello my friends. I have found this forum so useful that I have constantly finding solution on how to fix my Explorer.
So now I got 1 small problem and just cant find solution how to get it fixed.

Ok here it is

I have 2002 Ford Explorer XLS v6 4.0l

I have replaced

EGR valve
DPFE sensor

And still have a check engine lite on with 1 code
P0401 Exhaust Gas Recirculation Flow Insufficient Detected

Not sure if I have to check any vacuum hoses and dont know their location.

Any help what to check next would be greatly appreciated.

 

[zukman]

http://engine-codes.com/p0401_ford.html
copy that into your browser

 

[ssobel80]

http://www.obd-codes.com/p0401

This link should help you

 

[BayChaser]

zukman

That link I do know about. And still doesnt tell me allot just explains what can cause it. Now all I need to know what I can check for air leaks (location) or is there any other sensors that needs to be replaced.

 

[BayChaser]

http://www.obd-codes.com/p0401

This link should help you

Good read ssobel..

Thank you guys I will try go through all lines just to make sure that there are no cracks.

 

[MrBean]

just wondering if you deleted the code before you took it out for a test drive?

 

[BayChaser]

just wondering if you deleted the code before you took it out for a test drive?

Yep I did and it come back-- Same 1

 

[MrBean]

If you didn't find any vac leak and you replaced the valve and the sensor already then I guess electrical diagnosis is up next. It would be nice if you could find a wiring diagram for this system and start checking for continuity and all that.

 

[BigRondo]

I will check my shop manuals when I get home tonight for any pertinent wiring diagrams. I have a funny feeling that the emissions is in a manual that I don't have. Who knows

I'll post up anything I find. Stay tuned...............

 

[BayChaser]

I will check my shop manuals when I get home tonight for any pertinent wiring diagrams. I have a funny feeling that the emissions is in a manual that I don't have. Who knows

I'll post up anything I find. Stay tuned...............

Thank you so much that would help.

If you didn't find any vac leak and you replaced the valve and the sensor already then I guess electrical diagnosis is up next. It would be nice if you could find a wiring diagram for this system and start checking for continuity and all that.

Nope,, didnt find any leaks and I did take my time as well. Hope something comes up