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What Does My Check Engine Light Mean?

The most dreaded car repair for drivers is the check engine light. This yellow dashboard warning light can be mysterious in many ways because it can mean many things. The issues range in severity, which is why it is important to have it diagnosed as soon as it illuminates on the dash. Read on to learn about the top 5 common reasons why this light may be on!

1 - Loose, Broken, or Damaged Gas Cap

This problem is the one most people hope for because it is the cheapest and easiest to repair. When your gas cap is tightened properly, the gasoline can evaporate. It will signal the check engine light to come on.

2 - Faulty Oxygen Sensor

The O2 sensor sits in your exhaust pipe, and it simply reads oxygen levels. It sends the information to your vehicle's computer and uses the data to maintain a balanced air to fuel ratio for optimal engine performance.

3 - Broken Mass Airflow Sensor

The mass airflow sensor is all about perfecting the spark timing and fuel delivery. When the MAF sensor isn't functioning, it can lead to engine stalling, rough idling, increased fuel consumption, and more.

4 - Aged Spark Plugs

These mighty but small plugs produce the electricity to kickstart your engine. Spark plugs can grow old over time, and they can have build-up and reshape. When they've worn down, you should replace your spark plugs to allow smooth ignition.

5 - Bad Catalytic Converter

If you smell rotten eggs in your car and you have a lit check engine light, it is safe to assume that your catalytic converter is the issue. The catalytic converter is known for transforming engine fumes into safer vapors. When the cat is no longer reliable, the check engine light will come on to signal for repairs.


If your check engine light recently came on, please do not wait to bring your car to A & C Automotive & Machine for diagnostics. We'll get down to the bottom of the problem and get you the right fix so that you can be back on the road again.

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