I have a 97 Saturn SL1. I keep getting fault code P0401 exhaust gas recirculation insufficient flow. The valve is mounted on the exhaust manifold. There is no tube. I removed the valve and cleaned it, and put on a new gasket. The fault still hapens.

• P0401 Exhaust Gas Recirculation Flow Insufficient Detected - reduced flow might be caused by a sticking EGR valve or restricted/blocked EGR passages/ports.

Fix the code by finding and fixing the problem and then have the code cleared with suitable diagnostic equipment.

Diagnostic equipment with 2-way software would allow the EGR valve to be operated from the keyboard/screen and could make fault finding easier.

Here's a link on your P0301 code. P0301 OBD II Trouble Code Here's the link for the P0401 code. P0401 Saturn Exhaust Gas Recirculation Flow Insufficient your egr passage may be blocked.

The passages are plugged ! pull EGR valve an inspect passages and the pipe for a restriction or damage and repair as necessary.

code p0401 refers to exhaust gas recirculation(EGR) system-insufficient flow detected--- Causes ---hose leak/blockage, basic setting not carried out( if applicable)wiring--EGR valve/solenoid---ECM I would check the EGR valve solenoid first. Replace the faulty units with genuine one because most aftermarket units are not set for OEM cpu units and are not completely
compatible.

The code P0401 means P0401 Exhaust Gas Recirculation Flow Insufficient Detected.
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airbag reset tool also check fault code!

OBD-II Trouble Code P0401 - Insufficient EGR Flow

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

Check it and keep us updated. Hope this helps (remember to rating this free answer).

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:
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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

P0401 - Exhaust Gas Recirculation Flow Insufficient Detected

Possible causes - Harness or connectors (EGR volume control valve circuit is open or shorted.)
- EGR volume control valve stuck closed
- EGR volume control solenoid valve
- Dead (Weak) battery
- EGR passage clogged
- Exhaust gas leaks Possible solution - Clean EGR Valve
- Repair EGR harness or connector
- Replaced EGR volume control solenoid valve
- Replaced EGR volume control valve

More than likely you have a faulty EGR Valve Pressure Sensor, especially if your EGR Valve Pressure Sensor is the original metal type. The new sensor is made of plastic and doesn't corrode like the old design. This sensor is located on the Intake Manifold.



Here is the sensor: http://www.autozone.com/autozone/parts/2001-Mercury-Sable/EGR-Valve-Pressure-Sensor/_/N-jfkhrZ93y2i

It is also possible that the EGR Valve has a clogged port, but this is less likely.

I’m happy to help further over the phone at https://www.6ya.com/expert/jeremy_69f3cc28d95bf514

P1491= "exhaust gas recirculation valve insufficient lift."
P0401= "exhaust gas recirculation insufficient flow"
P1739= ""3rd clutch pressure switch" (automatic transmission code)

the exhaust gas recirculation (EGR) valve is vacuum operated. there may be a vacuum line that is broken or leaking or become detached from the EGR valve. any vacuum leak will cause the engine to run lean, leading to poor starting and idle cut-off due to lean fuel fuel mixture.

The EGR valve has a vacuum diaphragm inside it. this diaphragm could be leaking. the EGR valve will need to be replaced if this is the case.

The P1739 code shows that a problem with the 3rd clutch pressure switch or the wiring leading to the switch has been detected. It may be an intermittent fault. Reset the trouble codes and drive for a while and see if this code returns. If so, check the wiring and switch operation of the 3rd clutch switch.