Hyundai Check Engine Light – Common Causes and Fixes

Check engine light, the most feared thing in the car community… Because most of the time, it represents that you have a problem with your powertrain. And this problem can be a basic problem or a bad problem on the main parts. Here, we will explain the general causes and the solutions of the Hyundai check engine light. And if you are a Hyundai driver, this article will be very useful to you. 

Hyundai Check Engine Light Causes and Fixes 

Hyundai check engine light

There can be different reasons that cause the check engine light ıon Hyundai vehicles. And we need to state that the Hyundai vehicles are one of the rare vehicles that give the check engine light on the dashboard. These are the most common causes. 

Loose Gas Cap 

Yes. This is the most basic cause of the check engine light on ın your dashboard. If the gas cap is loose, your dashboard will give the check engine light.

Also, the solution to this problem is very simple. Just attach the gas cap tightly. And you will see that the light goes off. And we wish that the only problem that you have is this… 

Joke idea: If your friend has a car and loves it, you can make a joke! Just loosen the gas cap and make the check engine light open… Your friend will be shocked that his lovely car gives a check engine light problem 🙂 Do not hold this joke long, and say that you just loosened the gas cap 🙂 

Problems with Catalytic Converter

One of the most common causes of the Hyundai check engine light is the failing catalytic converter. The catalytic converter is a very common cause of the problem. They are the vital part of your vehicle that is responsible for reducing the bad emmisiıns and the exhaust sound. If the catalytic converter is clogged or damaged, your car can stall because of the inefficient expel of the exhaust gases. Also, you can hear weird exhaust sounds coming from your exhaust system if it is damaged. 


The common fix of the clogged the catalytic converter is, you can clean it by using cleaning agents. Even you can make it if you have a hydraulic or mechanical lifter and a wrench set. And also if you have damage to your catalytic converter, you need to change it with a new one. A typical catalytic converter change for Hyundai cars changes between $300-$500 including the labor. And you can also change the catalytic converter on your own. The OEM parts can range from $100-$150. And also you can find aftermarket ones around $50-$100. 

Spark Plug Problems 

Spark plug problem.
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Spark plugs can cause a problem with the Hyundai check engine lights. Also, spark plugs are the vital parts of car engines that are responsible for the ignition of the fuel inside the engine cylinders. So, if they will not work properly, the engine can not work. Also if you have a problem with a specific spark plug, you will feel performance loss and engine stall. 


The problem can be with the electrical system of your car. The spark plug mechanism is connected to the distributor mechanism of the car. If you have a problem with your distributor, you will probably have a problem with all spark plugs. Also if you have a problem with one spark plug, the problem can be with the electrical connections o that spark plug with the distributor. And also, you can have a problem with the spark plug itself. 

Checking the spark plug of Hyudait will price you around $100. Also if you have a problem with your distributor, it will cost around $250-$300. And if you consider the aftermarket parts instead of OEM parts, these prices can reduce by around 25% but we do not recommend it. 

Problem with Oxygen Sensor 

Also, the oxygen sensor is a very important and vital part of the car. They are placed on the exhaust system and measure the level of oxygen inside the exhaust gases. And send the level of oxygen level to the ECU system of the car. And ECU adjusts the best rate of the fuel and air mixture to get the best ignition in the engine cylinders. So if there is a problem with the oxygen sensor of the car, ECU can not adjust the required amount of fuel and air, and you will feel it as a performance loss in your engine. Also, you can have serious stalls if the problem is big. 


In most cases, the general fix of the oxygen sensor is changing with the new one. Also, oxygen sensor electrical connections can be problematic. Changing the cable connections can solve the problems. And also, just washing the oxygen sensor properly will solve the problem. If you are familiar with car mechanics, you can do it on your own without any problem. 

If you look at the OEM oxygen sensor prices of Hyundai, you can find the different kinds of them from $100. And also the labor cost will cost you around $150-$200. Before delving into solving the problem this way, you can clean the sensor on your own. 

Problematic Mass Air Flow Sensor 

Also if you have a problem with your mass air flow sensor, the Hyundai check engine light will blink. This means you have a problem with your mass air flow sensor. You can feel the problem of losing power in your engine. The MAF sensor must measure the mass air flow coming to the manifold and send this information to the ECU system of your car. And the ECU can adjust the level of fuel coming to your cylinders to get the best composition. 

So, if you have a problem with your mass air flow sensor, the symptoms will be the same with the oxygen sensor. 


The common fix for the faulty mass air flow sensor is changing it with the new one. Like the oxygen sensor, there can be problems with the electrical connections between the sensor and the battery. The change of these cables can solve the problem. 

In most cases, you can not change the MAF sensor. You need professional assistance for it. The aftermarket MAF sensırs of Hyundai can change between $50-$60. But if you want to buy an OEM part, the prices can be high as $150. And also add the labor to it, you will probably pay around $250-$300 for total repairs. 

Problems with Electrical Systems

The ideal working of the engine depends on the electrical system of your car. In the electrical system, distributor, alternator, and spark plug systems. So, if there is a problem with these systems, the engine of your car will not work. 

And all of these systems are connected to the battery of your car with cables. If there are problems with the cable connections, the electrical signals will not be transmitted through the cables. And this will cause serious problems. 


Changing the faulty elements of the electrical systems will solve the general problem that you have in your Hyundai cars. Changing cables will not be the huge money that we stated above. But if you have a problem with the systems that we explained above, you will minimum pay $150 for the total costs. 

Other Things to Know About Hyundai Check Engine Light 

You need to know that the Hyundai check engine light comes in certain conditions. So, you need to pay attention if you see that light. The problem can be huge. Also, different modes check the engine light. According to these different modes, you need to take different actions. 

Hyundai Check Engine Light is Constantly On 

If it is constantly on, you have a problem with the parts that we defined above. Maybe you will not feel any problems while you are driving. It will be very good if you bring your car to service immediately. ıf you continue to drive with these problems that we explained above, these problems can cause much bigger problems. 

Also if you are feeling the loss of performance issue with your car, you need to immediately pull over your car and get towed to the nearest service point. 

Blinking Hyundai Check Engine Light 

If the check engine light is blinking, it is about you having a major problem with your engine and powertrain system. You need to pull over your car safely. And if there are no service points around you, you need to make your car towed to a safe point. 

Last Words

As you see above, the Hyundai check engine light points out certain problems. You need to take care of the situation if you want to deal with bad conditions. 

Also, we gave slight estimations of the total costs of the repairs for each problem that you may have with your car. If you have additional comments and questions, please leave them below. 

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Uğur Uygun

Hello everyone, I am Uğur. I am a mechanical engineer who has experience in different R&D departments of HVAC companies. With my best friend, I decided to build this website to share out knowledge and experience. And also, I am interested in automotive. So, I am writing about automotive and automotive-related articles here. Sharing my knowledge and experiences on these topics is a very big pleasure for me. I am willing to answer all of the questions people have about these topics.

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