P0401 Trouble Code

[joe2job]

I know that pretty much everyone has already seen this question, but I can not for the life of me get the answer I need.

I'm getting P0401 (Insufficient Flow - ERG) on my 2001 Lincoln LS V6. I have done the following:

Replaced EGR Valve
Replaced DPFE Sensor
Replaced EGR Valve Gasket
Cleaned ports on Intake
Cleaned ports on Exhaust Manifold
Cleaned EGR Tube
Replaced hoses going from EGR Tube to DPFE Sensor
Checked vacuum hoses for suction - there is definitely suction
Run vacuum test on EGR valve - The engine stumbles with 10" of vacuum which tells me the flow seems to be okay

Basically what happens is I clear the code and it comes back on after 15-40 miles. No matter what, it comes back on. The only thing left for me to replace is the solenoid, but there seems to be plenty of suction coming through the vacuum hose (I also checked the vacuum hose and it is fine as well). There was a LOT of carbon completely blocking the port on the intake, but it has been completely cleaned. I have literally taken the entire system apart, replaced broken parts and cleaned the rest very thoroughly.

I am at my wits end with this stupid car and need any help that can be offered.

 

[dtools]

did you ever get an answer to this post ?

 

[joegr]

did you ever get an answer to this post ?

He posted once (the one post above) six years ago and he hasn't been back. I doubt he will be answering. Why don't you post the details of your exact problem, including what you have done so far.

Be aware that the OP had a gen I LS, and you have a gen II LS. The two EGR systems are very different.

 

[dtools]

You're very responsive and I appreciate that.....
The car is well maintained and very clean - 72K miles with all the service bulletins installed

A couple weeks ago, "check engine" light - OBD reports one fault - P0401
Cleared it - drove 10-20 miles - came back - no choking, stalling, missfiring, etc but I can detect sporadic hesitation from low speeds and sometimes while cruising.

Tried thus far
Removed the hose assembly from the EGR - Checked for cracked/brittle vacuum hoses - rubber boots look good
all tubes are clean - no obstractions - cleaned them anyways
Removed the EGR for visual - looks good with no rust/corrosion - gasket very clean as well - cleaned it an reinstalled
Cleared fault - drove it for 40miles or so - P0401 came back -
started doing a lot of reading on this forum and I'm hesitant to start throwing parts at it

- thanks for your help

 

[joegr]

There have been a few EGR assembly failures reported on here, including one of LSes.
Get Motorcraft, not aftermarket. Those who have tried aftermarket and reported it on here, reported that aftermarket didn't work for this part.

 

[grizzlyls]

Be aware, I just had my mech do a refresh on this system when he was doing the timing chain tensionor. He got in there and found a previous mech had done a hack job on my egr system. Makes sense since it failed smog 3 years back. Anyhow, he replaced all the hoses we could find since most of these are discontinued by ford. We found 3 (all with corrugated tubing) available at leftover parts places - that piece was not one of them. He showed me that not sure if it was bad, but I assume he put it back in. If you find one of these can you post the info - I might grab it as a spare since its so complex.

Edit: Doh

Never mind, I just noticed the OP was a v6. I am v8. Maybe a lead can be gotten still, but I imagine you will see same issues on availability on the v6 as well.

 

[joegr]

I think that you are mixing up the PCV system with the EGR system. There are no corrugated hoses/tubes associated with the EGR.

 

[grizzlyls]

I am sure I am. From what I saw it was all hacked up with electrical tape holding things together! I do remember him showing me a piece like that though.....

 

[dtools]

Replaced the EGR with Motorcraft - took care of it - thanks for your insight