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Can Spark Plugs Cause Check Engine Light? (Read This First!)

Check engine lights can be caused by several malfunctions in the vehicle. From malfunction of the oxygen sensor to many may result in check engine light. On the other hand, spark plugs can be damaged or worn out over the period. As time goes by, the spark plugs become old and torn.

Following the below tips, one may get an idea of what can cause the spark plugs to become damaged and if the check engine light is caused by spark plugs or not.

Can spark plugs cause check engine light?

Spark plugs can cause check engine light. Check engine light might be caused by several reasons, including the damage of spark plugs or even if they are torn out. Because torn spark plugs may cause misfires which results in flashing of the check engine light. It is better to change the spark plugs.

Spark plugs come with a vehicle, of course. Without spark plugs, the vehicle can not even start properly. The main purpose of the spark plugs is to create a spark. It’s more likely to ignite or mix the fuel so that enough energy is provided to the engine to start off.

Without spark plugs, the vehicle becomes really slow to start with. Even the fuel is not mixed well. As a result, it can even cause a misfire later, which results in the flashing of the check engine light. 

Even though check engine lights may be caused by several other reasons, spark plugs may be one of them.

Bad spark plugs:

Bad spark plugs do not mix the fuel properly. As a result, enough energy is not created to ride the vehicle smoothly. Any malfunctions like this may cause check engine light. 

Old spark plugs:

Moreover, as time goes by, the spark plugs also become torn. The old spark plugs also can result in check engine light.

Worn out spark plugs:

As the spark plugs ignite the fuel or air and provide energy, from time to time, it becomes worn out. Thus, can also lead to misfiring. 

Bad spark plug wires:

The same goes for bad spark plug wires. The misfiring may result in the flashing of light. Check engine light may indicate this malfunction.

Check engine light is mostly caused by gas emissions or by oxygen sensor problems. It also refers to serious problems, like damage to spark light. Once the spark light is damaged, the car loses its proper speed. It becomes slow, and later it may become uncontrollable.

All these may lead to greater problems. One may need to change the spark plug immediately. As the spark plug costs less, many may change it right away. Yet choosing the right size should be a priority. Every car may take different sizes of spark plugs. Do put a spark plug according to that.

If a check engine light appears, one should immediately take the car to the professional. They may check it and repair it accordingly. Otherwise, many may change the oxygen sensor first and later regret it.

Why spark plugs causes check engine light to come on?

Spark plugs can become torn and worn out with time. Later, results affect the overall performance and speed of the car. It is also responsible for causing check engine light. Even there are more malfunctions which can cause check engine light.

Below, some of the reasons why spark plugs cause the engine light to come on are included to provide a clear view.


Check engine light comes on due to several reasons. If there are faults in the spark plug or even the wires, it can lead to a misfire. Which later results in flashing of light as well as check engine light on. Any faults in spark plugs can lead to check engine light.

Well, the check engine light actually becomes flashy due to the problems in spark plugs.

Faulty plugs:

A faulty spark might lead to the triggering of the engine light. If the wire is torn apart or damaged, it can slow up the vehicle. Later the oxygen sensor might be damaged too. All in last triggers the engine light. As a result, it causes check engine light.

The sparks are the main reason here. Due to the sparks, the engine light reads codes and reacts to them. There are certain codes for certain situations which are detected by the engine light and appear as flashes depending on the problem.

As check engine light can be caused by other reasons too, better to consult a professional first.

What are the symptoms of spark plugs going bad?

Spark plugs can go bad due to the usage of many years. Like other instruments, spark plugs tend to go torn or worn out. It can also get damaged by time as a spark is created. Spark plugs provide energy to the car to run faster. Even to start the engine on, spark plugs are required.

There are certain symptoms that can say if the spark plug has gone bad or not. Some of those are listed below.

Car running slow:

As the spark plug provides sufficient energy to the engine to start off the car, the car tends to run slowly if there is a problem with the spark plug.

Check engine light:

Check engine light becomes flashy once the spark plug is damaged in some way. It might be a symptom of many malfunctions. That’s why it is better to repair the car immediately before any major problem occurs.

The engine runs on:

If there is a problem or the spark plug goes bad, the engine tends to react with it. Even if the car is not moving, the engine seems to work. As a result, it takes more fuel in return.

Hard to start:

While often starting, the car doesn’t start as if it might have a battery problem. Sometimes it is not the case. It might be due to the spark plug.

MPG drops:

As the spark plug has gone bad, the engine wastes more fuel. As a result, speed becomes slow, yet the fuel comes to its end sooner.

Overall performance slows:

The overall performance, even the speed, and acceleration become slow. As a result, it becomes difficult for the car to run for a long time.

What to do when the check engine light comes on?

Check engine light comes on for different reasons. Mostly any type of malfunction can cause the check engine light to come on. Many might not even understand what the problem is.

Well, the first thing to do is to slow down the car and lower the speed. Check engine light might refer to dangers too. As the check engine light appears, a code onboard the computer of the car also appears, which mainly refers to the problem.

Other than that, one can also check the battery, tighten up the gas cap and check all the cables. If the oxygen sensor doesn’t work, that can be changed too. The best way is to repair the car.

Only professionals can understand if there is a bigger problem or not. Otherwise, making decisions by yourself may not give any solution.

How to reset turned on check engine light for spark plugs?

Well, the check engine light can be reset even if the problem is not solved yet. One can do it by taking the car to the repair shop or else by themselves. As problems should be solved as soon as possible, it is better to take them to the repair shop. 

For temporary purposes, one can follow the below steps to reset the check engine light.

Disconnect the battery:

The easiest way is to disconnect both terminals of the batters. It allows the circuit to drain some energy. As a result, the codes might go too.

Reconnect the terminals:

After a couple of seconds, almost 30 seconds, one can reconnect the terminals and see if the check engine light is still on or not. Most probably, this may solve the problem. Or else run the car and let it reset the check engine light by itself.

Once the check engine light is gone, it will come back after a period. Better to repair it as soon as possible. If the light doesn’t come on again, you may need to hurry up.

Final thoughts:

Check engine light may be caused by many reasons, including spark plug-related problems. Even spark plugs get damaged over time and cause the car to slow down. Later affects the overall performance of the car. Any malfunction like this is immediately detected, and check engine light is caused.