That Dreaded Check Engine Light

by Margaret Minnicks 4 months ago in list

There are several reasons the check engine light might show up on your car's dashboard.

That Dreaded Check Engine Light

When the check engine light comes on in your vehicle, it might scare you, but there is no need to panic. You might be worried that something harmful might happen to your car before you can take it to a mechanic. You might also be worried that it will cost you an arm and a leg to get the problem fixed.

There are several reasons the check engine light might come on. Some of the reasons might not be as costly as you might think. Knowing in advance what the check engine light means might give you some peace of mind.

Signal that Something Is Wrong

The check engine light is a signal from the car’s engine computer that something has gone wrong with the car. The light is usually in bright orange, yellow or amber. One of these three colors does not mean the problem is more seriousness than the other colors. If you see a red check light come on, it is usually something serious.

Hopefully, you won't see the light flashing, because that indicates a more serious problem. If the light stays steady, the problem might not be a very serious one. However, you still should find out the reason that it came on. Most mechanics can run a diagnostic test that indicates a code that tells them what is causing the problem. The cost for the test is about $100.

Below are some of the top reasons the check engine light comes on. They are listed from the least expensive to the most expensive.

Loose Gas Cap

Photo by TireZoo via flickr

If you see the check engine light come on, the best problem to have is that your gas cap is loosed, damaged, or missing. The purpose of any gas cap is to seal the fuel system and to maintain pressure in the tank. If you don’t tighten the gas cap when you purchase gas or replace a faulty one, the car will lose fuel through evaporation.

If you tighten the gas cap yourself, it will cost you nothing. If the cap has to be replaced, the cost is very minimum. The average cost for a gas cap replacement is between $67 and $73. Labor costs are estimated between $17 and $23 plus taxes and fees.

Spark Plugs Should Be Replaced

Photo by David Pacey via flickr

All four spark plugs are needed to be in good condition for your car to run smoothly. If bad ones are not replaced, your car will run rough and lose power. If is best to get all four replaced at the same time even if only one is bad.

Clues that you have a spark plug problem might be slow acceleration, poor fuel economy, engine is misfiring, rough idle, and the car might be hard to start.

Changing spark plugs is a quick, easy and inexpensive fix. The average amount you will pay for spark plugs is between $16-$100, and the labor cost is from $40-$150.

Oxygen Sensor Needs Replacing

If your check engine light is on, you may have a bad oxygen sensor that should be replaced. If not replaced, your engine will burn more fuel than needed. Faulty sensors might cause damage to your spark plugs and catalytic converter.

Taking your car to a mechanic can cost up to $200, depending on the make and year of your car as well as the difficulty for mechanics to perform the task.

A Bad Mass Airflow Sensor

The mass airflow sensor measures the amount of air entering the engine to determine how much fuel is needed for the engine to run efficiently. Sometimes a mass airflow sensor should be replaced. If it isn't replaced, it could cause damage to other components of the car.

Almost all cars can run without a mass air flow sensor, but without one, the engine will not run smoothly.

The cost of a mass airflow sensor is about $300. The amount includes parts and labor.

Bad Catalytic Converter

Your catalytic converter is designed to protect the environment by converting harmful carbon monoxide into carbon dioxide. If the catalytic converter is bad, you will experience reduced performance and fuel economy. Besides, your vehicle will not pass an emissions test.

This is the most expensive reason a check engine light might come on. For most vehicles, the average cost of a catalytic converter repair is between $945 and $2475 including parts and labor. That amount might be so close to the car's value that car owners seek other avenues.

For Peace of Mind

There is no need to be stressed out if the check engine light comes on in your vehicle. It is a warning and not a death sentence for your car. If ignored, it could cause problems and you will end up having to pay much more to get it fixed. When the light comes on, it is best to have the vehicle serviced. Then, you will have peace of mind while driving.


I am not a mechanic, but I have experienced that dreaded check engine light several times on my 2001 Toyota Camry. I have the mechanic's invoices to prove it. I have done a lot of research on the subject and hope it never happens again. By the way, a loose gas cap has never been the reason my check engine light has come on.

Margaret Minnicks
Margaret Minnicks
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Margaret Minnicks

Margaret Minnicks shares articles with readers all over the world. Topics include celebrities, royal family, movies, television, foods, drinks, health issues, and other interesting things. Thanks in advance for TIPS that are sent my way. 

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