Emissions Test

[CeeJay Bailey 2]

I am still trying to get the Check Engine Light to stay off.



I have followed your advice of asking the mechanic for a code.



He says that the wording is Insufficient E... It had another word he couldn't see. It gave a code number of P0401.



Any help is appreciated. My tags and registration will expire very soon.



Thank you.

 

[Dre L]

P0401 OBD Trouble Code

Technical DescriptionInsufficient EGR Flow



What does that mean?EGR stands for Exhaust Gas Recirculation. It is part of the vehicle emmissions system, and is used to reduce combustion temperature and pressure to control Oxides of Nitrogen. There are generally three parts to the EGR system: the EGR valve, an actuator solenoid, and a differential pressure sensor (DPF). These things work together to deliver the correct amount of recirculation based on engine temperature, load, etc. The P0401 code means that OBD detected an insufficient amount of EGR.



SymptomsYou may notice drivability problems such as pinging (a.k.a. pre-ignition knock) when the engine is under load or the vehicle is at higher speeds. There may also be other symptoms.



CausesA code P0401 most likely means one or more of the following has happened:



The DPF (differential pressure) sensor is faulty and needs to be replaced

There is a blockage in the EGR (most likely carbon buildup)

The EGR valve is faulty

The EGR valve may not be opening due to a lack of vaccuum

Possible SolutionsIn fixing this code, it is quite common for people to just replace the EGR valve only to have the OBD code return. The EGR valve is not always the culprit.



Use a vacuum pump and pull the EGR valve open while monitoring engine RPM's. There should be a noticable difference in RPM's with the EGR open

Clean out the EGR valve to remove deposits

Replace the DPF sensor

Replace the EGR valve



Some Tracs have an extended warranty on the DPFE sensor. Check with your dealer, have them do the inspection while they're at it.



Probably wouldn't cost more than $100 to change both parts.



Below is a good link.



Buy a scangauge (www.scangauge.com).



Don't be afraid to change mechanics.

 

[Todd Z]

almost guaranty it is the dpfe sensor... Cost about 30 bucks, and you can change your self..

Todd Z

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[Tom Schindler]

Your mechanic is an idiot. Change out the DPFE sensor and be done with it.





Tom

 

[Kevin Palmer]

Like most here, we are pretty cautious to say negative things.



However, I have been following your posts and strongly reccomend that you go a mechanic that is "up to date" with his training and skills.



It is VERY easy to pull codes. With the code(s), at the very lest have a direction to go to do further tests to determine the cause(s).



The DPFE is a weak link on the Tracs. Ford has extended the coverage of them. Ford would not have done that if they were not an issue.



As noted above it is a simple fix if it is in fact the DPFE. $30.00, install it and your done.

You will need to clear or reset the codes. This can be done with a reader or, disconnect a battery cable and let it sit for a few minutes.



Good luck to you..

 

[Jeff C]

In case anyone's interested, I found a list of Ford ODBII codes and put it in my library.

 

[Teddy GreeneII]

Jeff, i saved that the last time it was up and forgot to say thanx. That's very handy for all of us to have.

 

[Tom Schindler]

Hell, Harbor Freight has an OBD-II reader for like $30.00.



I have a ScanGuage, I love it. Here is it mounted.

[Broken External Image]:





Tom