Nissan Emission Control Malfunction (Here Is How To Fix)

nissan emission control malfunction

If you own a Nissan vehicle, you may have experienced the anxiety-inducing moment when the check engine light illuminates on your dashboard.

This warning light signals that your car’s computer has detected a problem within the engine or emissions system. While it can be concerning, understanding the potential causes and appropriate actions to take can help you address the issue promptly and prevent further damage.

We will explore the common triggers for the Nissan check engine light, the severity of each situation, and the necessary steps to resolve the problem. By the end, you’ll have the knowledge to face this common automotive challenge confidently.

Understanding the Nissan Check Engine Light

The check engine light, often referred to as the Malfunction Indicator Light (MIL), serves as your vehicle’s communication tool to alert you of potential issues.

When the light turns on, it indicates that the car’s onboard diagnostic system has detected a problem related to the engine, fuel system, or emissions control. Depending on the nature of the issue, the check engine light can either remain steady or blink.

Understanding the distinction between these two scenarios will help you gauge the severity of the problem.

Steady Check Engine Light

If your Nissan’s check engine light remains steadily illuminated, it usually signifies a minor problem that requires attention but does not pose an immediate threat to your vehicle’s operation.

Common causes for a steady check engine light include a loose or missing fuel-filler cap, a potential emission control malfunction, or running out of fuel.

While you may continue driving your vehicle in these cases, it is advisable to schedule a service appointment with a Nissan dealer to diagnose and address the underlying issue.

Ignoring a steady check engine light could allow a small problem to develop into a larger, costlier one.

Blinking Check Engine Light

In contrast, a blinking check engine light demands immediate attention as it indicates a more severe problem that could potentially cause damage to your vehicle’s engine or emissions control system.

Examples of situations that trigger a blinking check engine light include an engine misfire or a malfunctioning catalytic converter.

When confronted with a blinking check engine light, it is recommended to pull over to a safe location and turn off the engine.

Contact your nearest Nissan service center for assistance and avoid driving the vehicle further to prevent exacerbating the issue.

Read also >> Engine Emission Malfunction (Signs, Causes + More)

Common Causes for the Nissan Check Engine Light

Multiple factors can trigger the check engine light in your Nissan vehicle, ranging from minor concerns to significant mechanical issues.

Understanding these common causes will empower you to identify the source of the problem and take appropriate action.

Loose or Missing Gas Cap

One of the most frequent triggers for the check engine light is a loose, broken, or missing gas cap. A faulty gas cap can disrupt the fuel system’s pressure and lead to fuel vapors escaping, resulting in reduced fuel economy and increased emissions.

If you suspect a loose gas cap, ensure it is tightly secured. After a few driving trips, the check engine light should turn off automatically. However, if the light persists, it is advisable to have your vehicle inspected by a Nissan dealer to rule out other potential emission control system malfunctions.

Failing Catalytic Converter

The catalytic converter plays a vital role in the emissions control system of your Nissan vehicle. Over time, it can become clogged with debris, especially in higher mileage cars.

A malfunctioning or clogged catalytic converter can negatively impact fuel economy and vehicle performance.

If you notice reduced power output, decreased fuel efficiency, or a lack of acceleration, it is crucial to have your catalytic converter inspected and repaired promptly to restore optimal functionality.

Faulty Spark Plugs or Spark Plug Wires

Spark plugs and spark plug wires play a significant role in the ignition process of your Nissan’s engine. Over time, these components can wear out, leading to engine misfires, reduced fuel efficiency, and potential starting issues.

If you experience rough idling, poor acceleration, or difficulty starting your vehicle, it may be indicative of faulty spark plugs or spark plug wires.

Replacing these components at regular intervals will help maintain the performance and efficiency of your Nissan.

Faulty Oxygen Sensor

The oxygen sensor, exposed to high temperatures in the exhaust system, measures the level of oxygen in the exhaust gases. This information is crucial for the engine control unit to maintain the optimal air-fuel mixture.

A malfunctioning oxygen sensor can cause your vehicle’s computer to supply too much or too little fuel, resulting in poor fuel economy, decreased performance, and potential engine damage.

If you notice a decrease in fuel efficiency or a persistent check engine light, it is essential to have your oxygen sensor inspected and replaced if necessary.

Faulty Mass Air Flow Sensor

The mass air flow (MAF) sensor monitors and controls the amount of air entering the engine, ensuring efficient combustion.

Exposure to dirty or particle-rich air can lead to MAF sensor failure, disrupting the air-fuel mixture and causing engine misfires, reduced fuel economy, and compromised performance.

Regular maintenance, including cleaning or replacing the MAF sensor when necessary, will help prevent issues associated with this component.

What to Do When Your Nissan Check Engine Light Comes On

When faced with a check engine light in your Nissan, it is crucial to take the appropriate steps to diagnose and resolve the issue promptly.

Ignoring the check engine light can result in poor drivability, reduced fuel economy, and potential damage to the emissions control system. Follow these guidelines to address the situation effectively:

Step 1: Evaluate the Severity

Upon seeing the check engine light, assess its behavior to determine the severity of the issue. If the light is steady, you may continue driving your vehicle while arranging a service appointment at your earliest convenience.

However, exercise caution, avoiding hard acceleration, deceleration, and excessive speeds. In contrast, a blinking check engine light indicates a significant problem requiring immediate attention. Pull over to a safe location, turn off the engine, and contact your nearest Nissan service center.

Step 2: Check for Loose Gas Cap

In cases where the check engine light is steady, a loose or missing gas cap could be the culprit. Ensure that the fuel-filler cap is tightly closed and secured. Additionally, verify that your vehicle has a sufficient amount of fuel, typically at least 3 gallons (11.4 liters).

After confirming these factors, continue driving your Nissan, as the check engine light should turn off after a few trips if the gas cap was the issue. If the light persists, schedule a vehicle inspection with a Nissan dealer to address potential emission control system malfunctions.

Step 3: Seek Professional Diagnosis

If the check engine light remains illuminated after verifying the gas cap and fuel level, it is advisable to have your Nissan inspected by a certified technician.

Nissan dealerships possess the necessary diagnostic equipment and expertise to identify the specific issue triggering the check engine light.

By reading the trouble codes stored in your vehicle’s computer, technicians can pinpoint the root cause and develop an appropriate repair plan.

Step 4: Address the Underlying Issue

Once the diagnostic process reveals the cause of the check engine light, take the necessary steps to address the underlying problem.

Depending on the nature of the issue, this may involve replacing faulty components, such as spark plugs, oxygen sensors, or catalytic converters.

Ensure that all repairs are performed by qualified technicians and adhere to Nissan’s recommended procedures to maintain the performance and reliability of your vehicle.

Step 5: Resetting the Check Engine Light

After resolving the issue triggering the check engine light, it is essential to reset the light to ensure it no longer appears on your dashboard.

Two common methods for resetting the check engine light include manually disconnecting your vehicle’s battery for approximately 10 minutes or utilizing an OBD-II scanner tool to clear the error code and reset the computer.

Whichever method you choose, ensure that the underlying issue has been resolved to prevent the light from reappearing.


The check engine light in your Nissan serves as an important indicator of potential engine or emissions system issues. By understanding the common causes for the check engine light and following the appropriate steps, you can address these problems promptly and prevent further damage.

Remember to evaluate the severity of the issue, check for loose gas caps, seek professional diagnosis when necessary, and address the underlying problem with the help of qualified technicians.

By taking these proactive measures, you can ensure the optimal performance, fuel efficiency, and longevity of your Nissan vehicle.

Steve P.

Steve is an automotive technician, technical writer, and Managing Editor. He has held a lifelong passion for cars, with a particular interest in cars like the Buick Riviera. Steve is based in Boise, Idaho.

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