OBD SCANNER CAME UP WITH FAULT P0401 EGR FLOW INSUFFICANT

Hi Joe

Like all solenoid valves, you can clean them with throttle body cleaner and then test the solenoid electronically with a 12 volt supply.

P0401 Exhaust EGR Flow Insufficient

Toyota Nation Forum https://www.toyotanation.com > threads > p0401-exha...
May 1, 2014 - The sensor is how the ECM determines there's insufficient EGR flow. It's on the intake-side of the system and if not enough exhaust-gases flow ...

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P0401 : EGR Flow Insufficient on 1996 Toyota Corolla

OBD-Codes.com https://www.obd-codes.com > forums > viewtopic
Jan 20, 2007 - on EGR codes, we recommend replacing the EGR, vacuum modulator and VSV (if equipped) and cleaning out the carbon buildup to the intake from the ...
If that finds nothing wrong, remove the EGR valve and bypass tube and check them for cleanliness and blockages. If they are blocked, follow your maintenance manual's instructions for cleaning them out so you do not damage the valve, then replace them and reset the ECM.

Insufficient EGR Flow - P0401 Code - Toyota

Looks like could be caused by one of several sensors.
I did find thisP04D9 EGR feedback saturation This OBD monitor indicates if the burned air fraction error is saturated against a high or low limit. The logic for the monitor evaluates the time spent at saturation and compares the ratio between the time spent in a saturation mode and the total time engine running. A fault is reported whenever the ratio exceeds the fault limit.
P04D9 EGR system: Feedback control(Saturated Low)
Enable conditions: Engine torque 300 - 2500NM,Exhaust Mass Flow 0.1 kg/s, Ambient Air Temperature-8 -55C, Barometric Pressure 75 - 105 kpa, Coolant Temperature>65 C
Disable Conditions No active DTCs P0069 P046c P0234, P0299, P0401, and P0402
Some possible causes
P0069 Intake manifold pressure sensor evaluation
P046c EGR differential pressure sensor: DP Sensor rationality
P0234 Comparison of actual boost pressure, Overboost, to modeled boost pressure
P0299 Boost Pressure: Underboost, Comparison of actual boost pressure to modeled boost pressure
P0401 EGR system (low flow)compare demanded egr flow to actual
P0402 EGR System (High Flow)compare demanded egr flow to actual

This video should help diagnose and fix EGR issues.
https://youtu.be/jZmJ54sDWJQ

You would need the flow chart for the code as it pertains to Chrysler products.
Code 401 means the computer is getting a low flow signal from the EGR valve sensor. The flow could in fact be low due to the EGR not opening, or the sensor could be faulty.

Depending on your Year and Model, there are some more prone to this Code than others because of the material used in the intake manifold. Ford and its affiliates switched from Aluminum to Plastic to prevent sooting.

On the old style 4.6L a passage under the Airhorn would clog and prevent EGR flow. Bad EGR flow is a Code 401. It can be a Solenoid valve failing to open, but many times it is a clogged passage as I mentioned. Sometimes a bad EGR has a ruptured diaphragm which can be checked by drawing the Vacuum out of it.

For those engines a simple $10 gasket and removal of 8 screws will allow you to scrape out the valley the passage is in.

So this fix is not real expensive, get parts at common autoparts stores.

Hi there:

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 helps.

code P0401 is an EGR code.
which is insufficient EGR (exhaust gas recirculation) flow.it is quite common for people to just replace the EGR valve.



You can try doing it your self.:----
To troubleshoot these issue and solve it yourself.I suggest you to go through few help links related to
OBD code P0401:-----
Click the link below:-----

1997 Chrysler Sebring: OBD Error Code P0401?

http://howtobyme.blogspot.in/2012/06/1997-chrysler-sebring-obd-error-code.html

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2004 Hummer H2: OBD Code P0141?

http://whoisbyme.blogspot.in/2012/06/2004-hummer-h2-obd-code-p0141.html

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DTC Trouble Code P0401?

http://schematicsdiagram.blogspot.com/2012/01/dtc-trouble-code-p0401.html

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These will help.
Thanks.

The P0401 code means that OBD detected an insufficient amount of EGR. BMW scanner can help you clear the fault codes.

This error means Exhaust Gas Recirculation Flow Insufficient Detected.

You can deatils on the following site http://www.permoveo.ltd.uk/tabid/122/OBD-Error-Code/P0401/Diagnostics/Hyundai/Default.aspx

but for convenience I have reproduced that information here:
.
Generic OBD Error Code Details for P0401 Exhaust Gas Recirculation Flow Insufficient Detected What does this mean? OBD Code P0401refers to
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. SymptomsPossible sumptoms of OBD code P0401
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. CausesPossible causes of OBD code P0401
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 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 & 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 CodesP0400 P0402 P0403

P00A0 is a factory readable only code (i.e. only ford dealers have the computer to read it)
the P0400 is a generic E.G.R. flow restriction code. so yes a dvom (multimeter) and a vacuum pump to diagnose it correctly, also check for loose wires as ford harness connectors are known to fail alot due to crappy phenolic content in the plastic and heat combined they can warp and / or corrode the contacts