Skip the auto shop - Our mechanics make house calls

Q: My car has two error codes

asked by on

I have two error codes. The first code is P0401, insufficient EGR flow detected. The second is P0401, warm up catalyst efficiency low, bank 2. What would it take to have these fixed?

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 two separate concerns going on with your Galant.

First, we will start with the code P0401, which represents insufficient EGR flow. There are a few different reasons that can cause this code to pop up. This includes lack of vacuum to activate the EGR valve, the EGR valve itself has failed, or there is a blockage in the EGR system preventing flow.

Now in regards to your second code, P0431, this represents a Warm Up Catalyst Efficiency Below Threshold signal. With this code, it is possible that the catalytic converter is no longer functioning efficiently and you may have an exhaust leak. There is also the chance that the oxygen sensor that monitors the catalytic converter is failing.

As you can see, there is a long list of possibilities that could be causing your Galant to give these codes. To be 100% certain, it may be time to enlist the assistance of a certified mechanic. They will be able to comprehensively inspect your vehicle and determine exactly why these codes are in your computer as well as assist you in making the necessary repairs to keep your vehicle running at its best.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Inner tie rod with tool cant remove

In order to remove the inner tie rods you have to use a tool to bend back the lock tabs that hold it locked in place. Once the lock tab is bent back then the remover tool can loosen the...

Q: Possible ECM problem

Hello! Im assuming the code was a P0606 which indicates a PCM/ECM processor internal fault. I suggest checking the wiring and terminal at the ECM because at times it will be just a bad connection/wire causing the trouble code. There...

Q: Engine light on code P0401

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 involves not just blocked passageways and...

Related articles

How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
P0052 OBD-II Trouble Code: HO2S Heater Control Circuit High (Bank 2 Sensor 1)
P0052 code definition HO2S Heater Control Circuit High (Bank 2 Sensor 1) What the...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...