OBD II code PO401 EGR Problem? Change Solenoid and pressure sensor; egr valve working good. Pressure sensor have 5 volt reference and ground; solenoide have 12 volt in red cable and negative is ok. Ford Van 250 1999

egr valve bad,P0401 OBD-II Trouble Code Technical Description 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. Symptoms 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 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 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 EGR codes: P0400, P0402, P0403, P0404, P0405, P0406, P0407, P0408, P0409

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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

DTC P0128 - Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)This means that the engine's PCM detected that the engine has not reached the required temperature level within a specified amount of time after starting the engine. The intent of the P0128 code is to indicate a faulty thermostat. Experience indicates that the most likely solution is to replace the thermostat.
DTC P0107 - Manifold Absolute Pressure/Barometric Pressure Circuit Low InputThe Manifold Absolute Pressure (MAP) sensor responds to changes in the intake manifold pressure (vacuum). 5 Volts is supplied to the sensor from the PCM (powertrain control module). Inside the MAP sensor is a resistor that moves in relation to manifold pressure. The resistor varies the voltage between about 1 volt to 4.5 volts (depending on engine load) and that voltage signal is returned to the PCM to indicate manifold pressure (vacuum).
This signal is essential for the PCM to determine fuel delivery. A P0107 DTC is set when the PCM sees that the MAP signal voltage is less than .25 volts which is too low. Confirm this measures conditions.

Keep in mind that will need using a scan tool with the Key on and engine running, monitor the MAP sensor voltage. If it is reading less than .5 volts, turn engine off, unplug the MAP sensor and, using a DVOM (Digital Volt/Ohm Meter) check for 5Volts on the 5 Volt reference circuit.


DTC P0401 - Insufficient EGR Flow
This fault code 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

Now, about the 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

Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer.



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Hi there:



P0401 OBD-II Trouble Code - 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.


Symptoms: 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


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




P0402 OBD-II Trouble Code - Exhaust Gas Recirculation Flow (EGR) Excessive Detected
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 P0402 code means that OBD detected an excessive amount of EGR.


Symptoms: You may notice drivability problems such as the engine may surge off idle. There may also be other symptoms.


A code P0402 most likely means one or more of the following has happened:
The DPFE (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 Solutions: with a P0402, it is common for people to replace the EGR valve, only to have the problem return. The most likely solution is to replace the DPFE sensor.


Check the voltage at the DPFE sensor both at idle and when the EGR is open
Replace the DPFE sensor

P1150 OBD-II Trouble Code - Air/Fuel Sensor Circuit Range/Performance (Bank 1 Sensor 2)


P1151 OBD-II Trouble Code - Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 2
upstream is considered the oxygen sensor for the right side exhaust manifold, before the catalytic convertor. Make sure the sensor's electrical connection is in good condition. On the sensor, test between the terminals with an multimeter/ohmmeter. You should see about 6 ohms at 68*F. If not, replace.

The reason your engine is doing that is because the sensor is failing in such a way that the computer is dumping in extra fuel when it isn't really needed. Then you get the black smoke.





Hope this helps.

The P0401 is an insufficient flow code and is almost always caused by the DPFE sensor. This sensor measures the back pressure in the exhaust as is a more accurate way of determining EGR flow than the old EGR position sensors. When the EGR valve opens the exhaust back pressure changes and the DPFE sensor informs the processor of this information. If the sensor isn't reading a change when the EGR valve is turned on through the solenoid, it will throuw a p0401 code. The only true way to check this is to install a scan tool and measure the DPFE voltage. Normal DPFE voltage is approx. .9 volts at idle.
The DPFE sensor dealer part price is approx. $140 but you will find cheaper prices at an aftermarket parts store. Good luck.

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.

Symptoms: 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: 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 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


Hope helps (remember to rate this answer).

Technical Description

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.
Symptoms

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

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 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

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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.

Symptoms
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
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 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

Re-Check the possible solutions and tell us news (remember rated this).

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.

Symptoms
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
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 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

Hope this help to solve it; remember comment and rated this help. TY for using Fixya.

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.


Symptoms
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
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 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


Hope this helped (remember comment and rated this).