Skip the auto shop - Our mechanics make house calls

Q: Engine light on

asked by on

My Engine light is on due to an error code P0401.

A: Hi there. A code P0401 indicates that the E...

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 this code will come up. Most of the time, the failure is due to a bad EGR valve or a failing EGR solenoid. I would typically use a computer scan tool to cycle the solenoid and see if it comes on. I could then see if the EGR valve is functioning by applying vacuum to it while the engine is running. This is best diagnosed with a computer scan tool. I would suggest getting some assistance from a certified mechanic from YourMechanic to make the repairs.

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: Electric motor actuator shaft

Hello there, thank you for asking about your 2013 BMW 135i. It sounds like the component the shop is describing is the camshaft timing solenoid. This solenoid is an electric motor that controls the position of the camshaft. The solenoid...

Q: Misfire on cylinder four

The number four cylinder would need to be checked for the misfire to see if it needs plugs, coil, or coil boots to fix the issue. It could also be that the plug has come loose, or blew out of...

Q: 1997 chevrolet lumina that has a p0401 code that is persistant

P0401 will often set if the passageway from the EGR valve to the intake is blocked with carbon. If you did not clear that passageway when replacing the EGR valve that is the most likely cause for the code. To...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.