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11Aug Reasons Why Your Check Engine Light Might Be On

6 Reasons Why Your Check Engine Light Might Be On

By NOLA AutomotiveRepairs | 0 Comments

Although your vehicle’s instrument cluster consists of several lights, the one that will surely make you do a second glance is the “check engine” light. It’s normal to drive for a long time without seeing this one come up, but once it does, the majority of drivers will feel a sense of dread.

What makes people worried about the check car engine light is that it is often associated with vehicular problems. It’s designed to warn drivers that there’s something wrong with its internals. However, it also doesn’t go into detail about it other than just letting you know that there’s a potential issue.

Neglecting this light could put you, your passengers, and your vehicle in danger. However, it may not always be an emergency that should be prioritized right away.

To give you an idea of what you can expect, here are 6 reasons why your check engine light might be on.

Reason #1: You Have a Loose or Faulty Gas Cap

One of the most minor problems that can cause your check engine light to illuminate is when you have a loose or faulty gas cap. You might find this funny, but a loose gas cap can mess with the emission system of a vehicle.

A faulty gas cap could cause fuel vapors to leak from the gas tank, which can lead to reduced vehicle efficiency overall.

The good news is that you can fix this problem on your own by simply checking to make sure that your gas cap is tight. In case you have a damaged gas cap, you can always have it replaced at an auto parts store for around $5 to $10.

Reason #2: Your Oxygen Sensor Might Need To Be Replaced

Another common cause for the check engine light to show up is when there’s something wrong with the car’s oxygen sensor. This device module is already a standard on all vehicles made after 1980. It is located in the emission control system of the car.

The job of an oxygen sensor is to make sure that the car’s engine follows the right amount of fuel consumption to ensure it’s operating at optimal ranges.

Sometimes, engine oil ash can accumulate and cover the oxygen sensor causing the check engine light to illuminate.

A blocked oxygen sensor can have a hard time monitoring your car’s fuel system and oxygen mix, eventually causing the vehicle to malfunction. Additionally, it may even cause harm to the air conditioning system.

You should get your oxygen sensor repaired by an experienced mechanic or by heading to a trusted auto repair shop. The cost for the parts and labor will usually run you around $200.

Reason #3: Your Spark Plugs Are No Longer Working

The spark plugs of a vehicle can last up to 200,000 kilometers. Their job is to provide sealing for the car’s combustion chamber and to ignite the fuel that goes through the engine.

6 Reasons Why Your Check Engine Light Might Be On

Faulty or misfiring spark plugs can lead to issues with the ignition system. This is another common reason why your car engine light turns on. You may even feel some form of jolting when you begin accelerating your vehicle.

Fortunately, these spark plugs are very easy and cheap to replace. You can find these parts for around $10 each and you can replace the old ones yourself.

Reason #4: You Have a Failing Catalytic Converter

The job of your car’s catalytic converters is to lower the emissions of the vehicle. It does this by converting the harmful gases the exhaust system produces and changes these into safer compounds. Many of these catalytic converters can last the lifetime of a vehicle, which is normally past 300,000 kilometers.

With that said, it’s still possible for your catalytic converter to be the source of your check engine light warning. Noticing any strange smells, lower engine performance, and less fuel efficiency are signs that your catalytic converter might have a problem.

Since catalytic converters aren’t intended to be replaced often, these parts don’t come cheap. You can expect to shell out more than $2,000 if you plan to have it replaced.

Reason #5: You Might Need To Replace Your Mass Airflow Sensor

If your air filter isn’t being replaced regularly, there’s a chance that your mass airflow sensor will malfunction. This device assists the computer of your car to input the right amount of fuel into the engine to improve efficiency and performance.

A faulty mass airflow sensor can lead to increased emissions, poor gas mileage, and could even cause your car to stall. That is why it’s crucial to get your car’s air filter serviced at least once a year.

Reason #6: The Exhaust Gas Recirculation (EGR) Valve Might Need To Be Replaced

Your exhaust gas recirculation (EGR) valve is designed to maintain low nitrogen oxide levels in the car. It does this by redirecting the vehicle’s exhaust system gas into the combustion chambers for it to cool.

Most of the modern cars we have nowadays all use electronically-controlled valves that automatically open and close. If there’s a problem with the flow, this could cause the check engine light to show up.

Causes Why Your Check Engine Light Might Be On

Carbon build-up in the valve can cause the system to get clogged. You can perform a visual check under the hood of your car but you can often hear or feel your engine stall when it idles.

Although it’s possible to get the exhaust gas recirculation valve cleaned, it’s not as accessible as other areas in your vehicle. Normally, drivers have their valves replaced along with a new gasket. These items can cost you close to $500 including labor.


The check engine light of your car is designed to inform you of any potential issues that can get worse if left alone.

There are many reasons why this display comes up but the most common are:
● A loose gas cap
● Faulty oxygen sensor
● Misfiring spark plugs
● Failing catalytic converter
● Mass airflow sensor problems
● EGR valve might need to be replaced

It’s important that you address the concern right away by doing a visual check and bringing your car to a trustworthy auto repair shop.

Getting help from a reliable mechanic can help you resolve your check engine light problem. Contact us to know more!

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NOLA Automotive Repairs has been serving New Orleans clients for nineteen years, making us one of the trusted auto repair shops in The Big Easy.
We offer a variety of services including engine repair, brake jobs, AC repair, and diagnostics.