5 Reasons Your Check Engine Light Is On

15 January 2021
 Categories: , Blog


When your check engine light comes on, you don't want to ignore it. It is best to drive your vehicle to an auto shop and get a diagnostic right away. A repair shop can hook up a diagnostic tool to your car and get a series of codes that tell them what is wrong with your vehicle.

1: Failing Battery

If your battery is failing and is not holding a charge properly anymore, the computer systems that run your vehicle may not be getting enough voltage. This will result in your check engine light coming on, as the computer isn't getting the power that it needs. 

2: Bad Oxygen Sensor

The oxygen sensor in your vehicle is designed to measure how much oxygen is not burned up in your exhaust system. This information impacts your gas mileage, as well as your catalytic converter. Most modern vehicles have multiple oxygen sensors, and your check engine light can be triggered if just one sensor goes bad. The cost to repair this depends upon how many oxygen sensors are bad and how quickly you fix the issue. If you don't fix the bad oxygen sensor, other systems can get damaged as well.

3: Catalytic Converter

The catalytic converter has an essential job. It is responsible for taking carbon monoxide and make it less harmful. A catalytic converter changes your emission into something less dangerous. If you want to run a clean vehicle and pass vehicle emissions tests, you need a working catalytic converter. Replacing your catalytic converter can be expensive to address.

4: Missing Gas Cap

Many modern vehicles are highly sensitive, and they can tell if your gas cap is missing, loose, or not fitting properly. A missing gas cap may not seem like that big of a deal, as there is usually a fuel door in place as well. However, fuel can evaporate without a gas cap before you use it, impacting your gas mileage and turning on your check engine light. This can be solved by simply putting on or tightening up your gas cap. If your gas cap is missing, you can order a new one.

5: Bad Mass Air Flow Sensor

Another reason your check engine light may be going off is because of a mass airflow sensor starting to fail. This sensor monitors your vehicle's air intake and then determines how much air should be injected into your fuel. It is a simple sensor that is affordable to replace. 

If your check engine light comes on, the best thing you can do is take your vehicle to your mechanic and have them read the codes. They will be able to let you know exactly what is wrong and help you fix the issue before it causes further damage. 

For more information, contact a local auto service, such as a Nissan service.