Why Is My Check Engine Light On?

The check engine light is every driver's worst nightmare. Not only does it mean that you need repairs, but it's very hard to narrow down the problem. You may have questions like, "What does it mean?" and "Is it something serious or an easy fix?" Below, we've listed the 5 most common reasons why a check engine light might come on.

Loose Gas Cap

A loose or missing gas cap is probably the first problem that you hope for when you see the check engine light because they are easy and inexpensive fixes. If the check engine light comes on immediately after you fill up, you should pull over to see if your gas cap is fastened. 

Oxygen Sensor Failure

The oxygen sensor, or O2 sensor, measures your exhaust's oxygen levels. If this part fails, your vehicle will continue to drive. However, your engine may overconsume gas, and the damages could end up spreading to your spark plugs or catalytic converter.

Faulty Catalytic Converter

The catalytic converter plays a vital role in your exhaust system; it takes dangerous gases like carbon monoxide and turns them into safer, breathable gases. Because this can impact your health, it's best you get the catalytic converter repaired ASAP.

Failing Spark Plugs

The spark plug provides the necessary start to ignite the mixture of air and fuel in the combustion chamber in your automobile. Odds are, your engine will misfire, and you will struggle to start your car. Our mechanics at Taylormade Automotive Inc can replace your spark plugs with no problem.

Mass Airflow Sensor Problem

Finally, a mass airflow (MAF) sensor measures how much air enters the engine. When it malfunctions, it will likely trigger the check engine light to come on. The Taylormade Automotive Inc. team can install a new MAF sensor and have your car back on the road again.


If your check engine light recently came, it is very likely that it is one of the five issues above. To be sure, you should bring your vehicle to our South San Francisco auto repair shop for a diagnostic test.

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