9 Reasons Your Check Engine Light Might Be On

No one likes to admit how often they put off getting their vehicle inspected after the check engine light comes on. Most drivers shrug and think, “It can’t be that serious.” With so many other alerts, the check engine light becomes a constant hum in the background to an otherwise, seemingly working vehicle.

The check engine light could be anything from a loose gas cap to a major engine problem. Why? One thing wrong with the engine can lead to multiple issues down the line, so the engine throws one code to tell you to immediately get your car inspected to avoid a breakdown.

If you’re frequently ignoring your check engine light, this quick list of 9 common reasons a check engine light comes on could help you tackle car maintenance faster. Remember – just because it could be something small doesn’t mean it isn’t something big.

Avoid breakdowns, expensive repairs, and multiple engine failures by troubleshooting your check engine light right away. Need more assistance? Our auto repair shop in Lisbon, MD can schedule you for car repairs. 

9 Reasons Your Check Engine Light Might Be On

Common Reasons Your Check Engine Light May Be On

Loose or Damaged Gas Cap

One of the simplest yet often overlooked reasons for a check engine light to come on is a loose or damaged gas cap.

Why does the check engine light come on for this? The gas cap seals the fuel system and maintains pressure; if it’s not tightly secured or if it is cracked, it can cause fuel vapors to leak out, triggering the check engine light.

While a loose gas cap doesn’t seem like a big deal, it can affect your vehicle’s fuel efficiency and increase emissions. Next time your check engine light comes on, inspect your gas cap and see if this solves your problem.

Faulty Oxygen Sensor

The oxygen sensor in your vehicle measures the amount of unburned oxygen in your vehicle’s exhaust system. Over time, this sensor can wear out, leading to inaccurate readings.

A faulty oxygen sensor can cause your engine to burn more fuel than necessary, negatively impacting your car’s fuel economy and triggering the check engine light to come on. Replacing a faulty oxygen sensor helps to ensure the best engine performance and avoid damaging your catalytic converter.

To check your oxygen sensor, grab a multimeter or head to your local auto repair shop to ensure your car is reading the oxygen correctly and isn’t damaging your car.

Catalytic Converter Issues

Your catalytic converter helps to reduce harmful emissions in your vehicle. It works by converting carbon monoxide into carbon dioxide. If it’s malfunctioning, you might notice a decrease in fuel efficiency, engine performance, or even a rotten egg smell coming from your exhaust.

Ignoring catalytic converter issues can lead to severe engine damage and failure to pass emissions tests. If the check engine light is on because of a catalytic converter issue, pay attention to your fuel economy, overall engine performance, or seek a diagnostic test from your local auto repair center.

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Malfunctioning Mass Airflow Sensor

The mass airflow sensor in your vehicle monitors the amount of air entering the engine and helps determine how much fuel to inject for proper combustion. A malfunctioning MAF sensor can lead to poor fuel economy, rough idling, or even engine stalling.

Your check engine light will alert you to a mass airflow sensor issue to help avoid engine stalling or other complications. Replacing the MAF sensor can restore your vehicle’s performance and prevent further complications. If you notice any issues with your engine, even just hard to start, and your check engine light is on, this could be the issue.

Worn Spark Plugs or Ignition Coils

Your engine relies on spark plugs and ignition coils to ignite the air-fuel mixture in the combustion chamber. Over time, spark plugs and coils can wear out, leading to misfires, reduced power, and increased emissions.

Replacing worn spark plugs or ignition coils can resolve a check engine light in some cases and keep your engine running smoothly. Always check the spark plugs by visiting a local auto repair shop.

Faulty EGR Valve

The exhaust gas recirculation (EGR) valve reduces nitrogen oxide emissions by recirculating a portion of the exhaust gases back into the engine’s cylinders. A faulty EGR valve can cause the engine to run rough, stall, or emit more pollutants.

A common reason for the check engine light, an EGR valve needs to be fixed ASAP to ensure your car isn’t running too rough, won’t fail emissions, and is fuel efficient.

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Transmission Issues

While transmission problems are often associated with specific warning lights, they can also trigger your check engine light. Issues like slipping gears, rough shifting, or transmission fluid leaks can cause the light to come on to alert you to potential engine issues if the problems aren’t fixed.

If you suspect a transmission problem, it’s important to have it diagnosed and repaired by a professional auto shop to avoid more serious damage.

Vacuum Leak

A vacuum leak occurs when unmetered air enters the engine, disrupting the air-fuel mixture. This can lead to rough idling, poor acceleration, or even engine stalling.

The check engine light may come on as the engine control module detects an imbalance in the mixture. Locating and fixing a vacuum leak can be challenging, but it’s crucial for maintaining optimal engine performance.

Your local auto shop can run engine diagnostics to see if a vacuum leak is the issue and recommend auto repairs to keep everything working correctly.

Faulty Battery or Alternator

A failing battery or alternator is another common issue for the engine light to come on. Electrical problems can lead to a wide range of issues, from dimming lights to difficulty starting the engine.

Ensuring your battery and alternator are in good condition can prevent unexpected breakdowns and keep your vehicle’s electrical systems functioning properly. Sometimes, to fix your check engine light, you just need to replace an old battery or update your alternator. A local, reputable mechanic can ensure this is the problem before you invest in new parts for your car.

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Don’t Leave the Check Engine Light On - Get Repairs Today

Understanding why your check engine light is on can help you take the right steps to diagnose and fix the issue before it escalates into a more serious problem. Regular vehicle maintenance and timely repairs can keep your car running efficiently and safely and help avoid unexpected breakdowns, dash warning lights, and more.

Lisbon Auto Center is happy to run an engine diagnostic if your check engine light is on and you don’t know why. We help out with affordable, fast services you can trust.

FAQ

1. What are common reasons for a check engine light to come on?
The check engine light can come on for many reasons, ranging from minor issues like a loose gas cap to more serious problems like a faulty oxygen sensor, a failing catalytic converter, or issues with the spark plugs and ignition coils. Most engine problems can be diagnosed quickly by a trained auto professional.

2. Is it safe to drive with the check engine light on?
It depends on the severity of the issue. If the check engine light is steady and the car seems to be running normally, you may be able to drive a short distance to a repair shop. However, if the light is flashing or the vehicle is running poorly, it’s best to stop driving and have it checked immediately. Do not leave your check engine light on for more than a few days before scheduling an auto repair appointment.

3. How can I diagnose the problem causing the check engine light?
Many auto shops in Maryland offer diagnostic services where they use an OBD-II scanner to read the error codes from your vehicle’s computer. These codes can pinpoint the exact issue, helping you understand what needs to be repaired. In the mean time, you can troubleshoot your gas cap, listen to the engine, check your battery, and replace your spark plugs to see if these correct the issue.

4. How much does it cost to repair a check engine light issue?
The cost can vary widely depending on the problem. Simple fixes like tightening a loose gas cap or replacing a small part may cost under $100. More significant repairs, such as replacing a catalytic converter, can run into the hundreds or even thousands of dollars. The earlier you inspect the issue, the quicker you can budget and plan for repairs.

5. Can I reset the check engine light myself?
While it’s possible to reset the check engine light by disconnecting the battery or using an OBD-II scanner, this doesn’t solve the underlying issue. If the problem isn’t fixed, the light will likely come back on. Your car may fail emissions if the issue isn’t fixed or you could face an unexpected breakdown.

6. How do I choose a reliable auto repair shop in Maryland for check engine light repairs?
Look for a shop with certified technicians, good reviews, and transparent pricing. It’s also helpful to ask if they offer warranties on their work and if they have experience with your specific make and model. Lisbon Auto Repair is happy to provide a quote today.

7. How long does it take to fix a check engine light issue?
The repair time depends on the nature of the problem. Minor issues may be fixed within an hour, while more complex repairs could take a day or longer. Come in to Lisbon Auto for an estimate, schedule, and quote to help you get back on the road.

 

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