Question about 1998 Mercury Sable
P0401 OBD-II Trouble Code - Insufficient 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 EGR (DPFE). 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.
You 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.
A code P0401 most likely means one or more of the following has happened:
* The DPFE (differential pressure feedback EGR) sensor is faulty and needs to be replaced
* There is a blockage in the EGR (tube), most likely carbon buildup
* The EGR valve is faulty
* The EGR valve may not be opening due to a lack of vaccuum
In 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 & DPFE voltage. There should be a noticable difference in RPM's with the EGR open
* Clean out the EGR valve and/or tubing to remove deposits
* Check the voltage at the DPFE, compare to specified values (refer to a repair manual for your specific model)
* Replace the DPFE sensor (with a good quality / OEM one)
* Replace the EGR valve
Hope this help to solve it; remember comment and rated this help. TY for using Fixya.
Posted on May 06, 2010
Insufficient EGR flow -usually the egr valve gets carboned up and start clogging,actuator fails or valve sticks u can remove valve and clean carbon off valve and tube which usually fixes problem also can be a vacuum problem to egr valve test vacuum at valve
Posted on May 06, 2010
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
Here's a link to this great service
Posted on Jan 02, 2017
Tips for a great answer:
Aug 08, 2017 | Mercury Cars & Trucks
Jul 16, 2014 | 2001 Mercury Sable
Jul 21, 2010 | 1998 Mercury Sable
Apr 05, 2010 | 1999 Mercury Sable
Mar 28, 2010 | 1998 Mercury Sable
Feb 21, 2010 | 1998 Mercury Sable
Dec 04, 2009 | 1998 Mercury Sable
May 30, 2009 | 2001 Mercury Sable
551 people viewed this question
Usually answered in minutes!
Step 2: Please assign your manual to a product: