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P0401

Hi there. A code P0401 indicates that the EGR system is not working properly. The EGR, or exhaust gas recirculation system, is used for emissions to reduce the NOX emissions. If it's not functioning and opening as it should, then...

Hello, thank you for writing in. If the vehicle was in a wreck, the issues are likely independent from each other. One issue seems to be a powertrain control module electrical malfunction. This could be an issue with an input...

Hello. Typically when you get this code it is because you have low flow in the EGR system. If the EGR valve is good and if the tube is clear then you either have a clog in the intake manifold...

Hi there. The Engine Gas Recirculation (EGR) valve could be sticking or full of deposits from the exhaust system. Remove and clean the EGR valve before replacing it to see if the system will begin to operate. The oxygen sensors...

The light will not go away until the P0401 code (https://www.yourmechanic.com/article/p0401-obd-ii-trouble-code-exhaust-gas-recirculation-flow-malfunction-by-jay-safford) is cleared from memory with a scanner. You should check the two heat resistant hoses that go to the DPFE sensor or the EGR sensor that goes down to...

Engine code P0401 on your Honda Accord indicates that there is low flow to the EGR valve. The repair for this is to remove the EGR valve and, using a special tool, cleaning the passages of the EGR tube. In...

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Insufficient EGR flow is probably not the cause of the rough or low idle and thus is just a coincidental fault. You should repair it and perhaps first, just to be absolutely sure, but rough idle is more likely due...

Assuming that the passageways, including any through and within the plenum and intake are truly completely clear, there is likely a problem with other EGR system components. On your vehicle, Diagnostic Trouble Code P0401 (https://www.yourmechanic.com/article/p0401-obd-ii-trouble-code-exhaust-gas-recirculation-flow-malfunction-by-jay-safford) involves not just blocked passageways...

Hello. The codes P0421 (https://www.yourmechanic.com/article/p0421-obd-ii-trouble-code-warm-up-catalyst-efficiency-below-threshold-bank-1-by-andrew-quinn) and P0401 (https://www.yourmechanic.com/article/p0401-obd-ii-trouble-code-exhaust-gas-recirculation-flow-malfunction-by-jay-safford) refer to the oxygen sensor (https://www.yourmechanic.com/services/oxygen-sensor-replacement) and EGR valve (https://www.yourmechanic.com/services/exhaust-gas-recirculation-egr-valve-replacement), respectively. It is possible that an issue with one is causing the fault to be seen by the other, as they will...

The first thing to check is to see if the EGR solenoid will release the vacuum when the electrical connector is disconnected. If it still doesn't release the vacuum then the solenoid should be replaced. The codes need to be...

Getting a hold of the OBD codes is definitely a great first step to diagnosing your Mitsubishi, but it must be noted that OBD codes are only a starting point, not a diagnosis. The codes P0401 and P0431 are actually...