What I did is added seafoam through pcv valve vacuum line, about 1/2 a can and the rest to gas tank. Did not have to disconnect battery to clear the codes after seafoaming. The code P0401 disappeared after about 2 days.Thanks redbeard00,
What I did is added seafoam through pcv valve vacuum line, about 1/2 a can and the rest to gas tank. Did not have to disconnect battery to clear the codes after seafoaming. The code P0401 disappeared after about 2 days.
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Your SUV is really giving you a hard time, lol. Sorry but I've had those days too. I would try to check if you have blocked EGR passages. If ok check for restricted MAP sensor vacuum hose/passage or restricted exhaust. I know you replaced the CAT but if the muffler is blocked then there would still be a restriction. Also check the wiring and connection to the MAP sensor.
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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.
If you have replaced the EGR valve multiple times and followed the GM trouble chart, but the P0401 insufficient EGR flow code continues to recur on your 2000 Impala LS 3.8, there are a few other things you can check:
Check for clogged EGR passages: Make sure that the EGR passages in the intake manifold are not clogged with carbon buildup. Use a vacuum gauge to check for proper vacuum at the EGR valve to ensure the passages are clear.
Check the EGR solenoid: Make sure that the EGR solenoid is functioning properly. You can use a multimeter to test the solenoid's resistance and check for proper voltage and ground signals.
Check the vacuum supply: Make sure that there is adequate vacuum supply to the EGR valve. A vacuum leak or restriction in the vacuum line can cause insufficient EGR flow.
Check the catalytic converter: A clogged or damaged catalytic converter can also cause insufficient EGR flow. You can test the converter's efficiency using a digital thermometer.
Check the wiring and connectors: Make sure that all wiring and connectors related to the EGR system are in good condition and properly connected.
If none of these steps resolve the issue, it's possible that there is a problem with the PCM. You may need to have the PCM tested or replaced by a qualified mechanic.
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
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
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.
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).
but for convenience I have reproduced that information here: . Generic OBD Error Code Details for P0401Exhaust 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
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 (DPF). 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.
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 (DPF). 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.
Thanks redbeard00,
What I did is added seafoam through pcv valve vacuum line, about 1/2 a can and the rest to gas tank. Did not have to disconnect battery to clear the codes after seafoaming. The code P0401 disappeared after about 2 days.
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