Lexus P0401 Exhaust Gas Recirculation Flow Insufficient Detected

Description

OBD-II Trouble Code Description for P0401 Lexus

Exhaust Gas Recirculation Flow Insufficient Detected

What does this mean?

OBD2 Code P0401 Lexus definition:
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 Lexus code means that OBD detected an insufficient amount of EGR.

Symptoms

Possible sumptoms of OBD code P0401 Lexus
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.

Causes

Possible causes of OBD code P0401 Lexus
A code P0401 Lexus 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

Possible Solutions

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

Related Codes

P0400 Lexus P0402 Lexus P0403 Lexus


The OBD2 Code Information Be Applicable For Lexus:

2013 Lexus RX 450h F Sport,2013 Lexus RX 450h,2013 Lexus RX 350 F Sport,2013 Lexus RX 350,2013 Lexus LX 570,2013 Lexus LS EU-Version,2013 Lexus LS 600h L,2013 Lexus LS 460 F Sport,2013 Lexus LS 460,2013 Lexus LF-NX Concept,2013 Lexus GS 450h F Sport,2013 Lexus GS 450h,2013 Lexus GS 350 F Sport,2013 Lexus GS 350,2013 Lexus GS 250,2013 Lexus ES 300h,2013 Lexus ES350,2012 Lexus LF-LC Concept,2012 Lexus LF-CC Concept,2011 Lexus LFA,2011 Lexus LF-Gh Concept,2011 Lexus IS 350 F Sport,2011 Lexus IS 350,2011 Lexus CT 200h,2010 Lexus SC 430,2010 Lexus RX 450h,2010 Lexus RX 350,2010 Lexus LS 600h,2010 Lexus LS 460 Sport,2010 Lexus LS 460 L,2010 Lexus IS250C,2010 Lexus HS 250h,2010 Lexus GX 460,2010 Lexus GS 460,2010 Lexus GS 450h,2010 Lexus GS 350,2010 Lexus ES 350,2009 Lexus SC430,2009 Lexus LS,2009 Lexus LS460,2009 Lexus LF-Ch,2009 Lexus IS 350,2009 Lexus GX 470,2009 Lexus GS 460,2009 Lexus GS 450h,2009 Lexus GS 350,2008 Lexus LX 570,2008 Lexus LS 600h L,2007 Lexus LS,2007 Lexus LF,2006 Lexus SC,2006 Lexus IS350,2006 Lexus GS,2005 Lexus RX400h,2005 Lexus LFA Concept,2005 Lexus ES330,2004 Lexus RX330,2004 Lexus LS430

 

Note:

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