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Why is my check engine light flashing in my Fairfax, VA based vehicle?

October 1, 2021

Why is my check engine light flashing in my Fairfax, VA based vehicle?

If your vehicle’s check engine light is flashing, it’s imperative to find a safe place to pull over, park your car and turn off your engine. A flashing check engine light usually means your vehicle needs an immediate repair and it’s no longer safe to drive.

There are multiple reasons why your check engine light could be flashing so keep reading to better understand what your vehicle is trying to communicate to you.

Why Is My Check Engine Light Flashing?

A check engine light could illuminate for a number of reasons. The most common reasons include:

1) A failing catalytic converter – The main role of a catalytic converter is to synthesise carbon dioxide from carbon monoxide particles. A malfunctioning converter causes poor engine performance and below average fuel efficiency. This would also prevent your car from passing an emissions test.

Signs your vehicle might have a failing catalytic converter:

  • Vehicle is moving sluggishly
  • Isn’t accelerating like usual 
  • Emitting black exhaust that smells like sulfur

2) Faulty mass airflow (MAF) sensor – The Mass Airflow sensor monitors the amount of air entering the engine to efficiently determine how much fuel is needed to run the engine. 

With a bad airflow sensor, you can still drive your car, though fuel economy and performance will certainly deteriorate. Luckily this isn’t too severe of an issue, as replacing an airflow sensor and air filter can be done quickly and easily by a trained auto technician or mechanic.

3) Needs a new oxygen (O2) sensor – Your vehicle’s oxygen sensor has an important job: to monitor how much oxygen and unburned fuel is exhausted. Like the airflow sensor, a broken oxygen sensor won’t stop you from driving your car, though it will lower your MPGs and gradually do damage to your catalytic converter. And because catalytic converters are expensive, it’s best to replace any bad O2 sensor before the damage is done.

4) Spark plugs need to be replaced – Spark plugs and wires play a pivotal role in the engine. They work together to ignite the air-fuel mixture in the combustion chamber and transfer the spark from the ignition coils to the plugs. Faulty spark plugs or wires can also damage the engine, ignition coils, oxygen sensors and clog the catalytic converter.

Unfortunately, the symptoms of dead spark plugs are similar to many other car warning signs: 

  • Stalling
  • Bad fuel efficiency
  • Poor performance
  • Rough idling

That’s why it’s important to review your car light symbol meanings and investigate further with an OBD II diagnostic tool.

Of course, without a proper inspection, your flashing check engine light could mean something else is wrong, like faulty ignition coils, a bad ECM, or something as simple as a cracked hose. 

a red check engine light diagnostic tool

This is why it’s important to have your vehicle inspected as soon as possible.

ABS Unlimited is here to help! We have experienced and trusted technicians available to run diagnostics and fix the problem. Time is of the essence when it comes to a flashing check engine light, so be sure to schedule an appointment ASAP.