Why is the Check Engine Light On?


The check engine light is one of those things in life that are unnecessarily feared. This little orange light is actually doing you a pretty big favor by letting you know there is a small problem onboard. More than likely it will be a simple, inexpensive fix, that is of course, as long as you take care of the problem as soon as it becomes apparent. In order to keep repairs to a minimum be sure that you head to a professional auto repair shop for diagnostics as soon as that pesky little light turns on. The following are 5 of the most common reasons a check engine light will illuminate.

Faulty MAF Sensor

The mass airflow sensor measures incoming air and determines how much of it needs to be mixed with gasoline in order to create the right air fuel mixture to make the engine run properly. If the sensor becomes damaged or dirty or if the air filter becomes clogged it will not be able to take proper readings which will likely result in your vehicle using excessive amounts of gasoline which will drastically reduce your fuel efficiency.

Malfunctioning Oxygen Sensor

The oxygen sensor, like the MAF sensor, helps calculate the correct air and fuel mixture, but it does it from the other end. This sensor is located in the exhaust and measures oxygen in the emissions of the vehicle. The more 02 it detects the more gas it assumes needs to be used, which can result in decreased fuel efficiency. The usual cause of a malfunctioning oxygen sensor is an exhaust leak, which is bad for you and your car.

Misfiring Spark Plugs

The spark plugs are what ignite the air and fuel mixture inside the combustion chamber. If they become dirty or corroded they may spark at the wrong time, which will result in a very rough running engine.

Cracked or Loose Gas Cap

The best thing you can hope for if the check engine light comes on is that you forgot to tighten the gas cap after filling up. This will trigger the check engine light because gasoline will be evaporating out of the filler hose.

Faulty Catalytic Converter

One of the most detrimental repairs that could result from the check engine light is the need of a new catalytic converter, which converts harmful exhaust gases into less hazardous emissions. This part is very expensive to repair, however it won't fail unless something else went wrong before it, likely a much small problem which would have likely triggered the check engine light first. This is why it is important to always have check engine light diagnostics completed as soon as the light comes on.

If your dashboard service light is staring you down and you need check engine light diagnostics in Sacramento head to Freeport Automotive. We use modern equipment to pinpoint problems, ensuring fast and accurate auto repair. Give us a call at (916) 389-2405 to request an appointment for superior auto maintenance in Sacramento today.

Freeport Automotive Blog

Written By Brian Corey

Published By MORBiZ