Q: Check engine light is on. I took it to AutoZone and told me it is the code P0401. Is it safe to drive until next week?

asked by on June 30, 2017

Check engine light is on. I took it to AutoZone and told me it is the code P0401. Is it safe to drive until next week?
My car has an automatic transmission.

Hi There, Code P0401 relates to the EGR valve flow. When this code is triggered, the computer has detected that the flow is insufficient. Driving the car until next week will not cause any harm, although the vehicle may not run well. The EGR valve. allows the flow of exhaust gases into the intake manifold in controlled amounts. When you start the motor, the valve remains in a closed position, blocking the flow of exhaust gases. Once the engine reaches operating temperature and speed increases, the valve, either through vacuum or electronic control will gradually open, allowing burned exhaust gases to enter and combine with the air-fuel mixture inside the combustion chamber. When the EGR valve is clogged or dirty, as they are prone to, it may not function properly causing the engine to idle rough, stall at idle speeds, cause the car to get poor fuel mileage, or emit a strong smell of fuel due to excess hydrocarbons which also results in failing emissions tests. I would suggest having an expert from YourMechanic come to your location to diagnose and inspect your vehicle.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

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

Engine is misfiring on my car

A faulty mass air sensor can cause rough running due to the injection mapping being improperly set. Unplugging the sensor can, in some cases, cause the rough running to clear up as a fault is set and the engine computer...

Service Engine Soon light staying on.

Evaporative systems seal the tank off from atmosphere and purge through the intake while the engine is running, if the computer senses that one of the valves electrical or mechanical functions aren't appropriate it will set a check engine light...

HVAC Blower Motor Fan runs on high Speed all the time

This may be related to a faulty blower motor control module or resistor. The blower motor resistor controls the various speeds and functions of the blower motor once it is turned on. I would recommend having an expert from YourMechanic...

Related articles

Mercury Certified Pre-Owned (CPO) Car Program
Drivers Drivers who are shopping around for a used Mercury vehicle may want to check out cars under their certified pre-owned program. Many manufacturers have a certified pre-owned (CPO) program, and each one is set up differently. Read on to...
Understanding the Mercury Intelligent Oil Life Monitor and Service Indicator Lights
Car symbols, or dashboard lights, are a car service reminder. The Mercury Intelligent Oil Life Monitor indicates when and what service your car needs.
How Long Does a License Plate Light Last?
Making Making sure that your car is safe and road ready should be one of the top concerns that you have. The more you are able to find out about the various safety features on your vehicle, the easier you...