Mitsubishi P0420 Code: What it Means, Its Causes and How to Fix It

If you own a Mitsubishi and have been experiencing issues with your vehicle’s catalytic converter, then you may have come across the P0420 code. This code indicates that there is a problem with the catalyst system efficiency below threshold bank 1. In this article, we will discuss what this code means, its causes, and how to fix it.Most models of Mitsubishi cars will work with the fixes we will discuss for the P0420 code. This includes popular models such as the Mitsubishi Lancer, Outlander, Eclipse, and Mirage. These fixes are applicable to both older and newer models of Mitsubishi cars.#ERROR!

Mitsubishi P0420 Code: What it Means

The Mitsubishi P0420 code indicates that the catalyst system’s efficiency is below the threshold for Bank 1. This means that the catalytic converter is not working as efficiently as it should be, resulting in increased emissions. The catalytic converter is responsible for converting harmful pollutants in the exhaust gases into less harmful ones before they are released into the atmosphere. When the converter fails to do so, it triggers the P0420 code. The causes of this code can range from a faulty catalytic converter to a malfunctioning oxygen sensor or exhaust leak. To fix this issue, one needs to diagnose the root cause and replace the faulty component.

Signs and Symptoms of Mitsubishi P0420 Code

The Mitsubishi P0420 code is a generic powertrain code that indicates a problem with the catalytic converter’s efficiency. The catalytic converter is an essential component of the exhaust system that helps reduce harmful emissions. When the catalytic converter fails to function correctly, it can cause several symptoms that can affect the vehicle’s performance and fuel economy. Here are some of the signs and symptoms of the Mitsubishi P0420 code:

• Check Engine Light: The most common symptom of the P0420 code is the illumination of the check engine light on the dashboard. The light may come on and stay on or flash intermittently.
• Reduced Engine Performance: A faulty catalytic converter can cause a reduction in engine performance, resulting in poor acceleration, stalling, or hesitation while driving.
• Increased Emissions: A malfunctioning catalytic converter can cause an increase in harmful emissions, which can lead to a failed emissions test.
• Decreased Fuel Efficiency: A faulty catalytic converter can cause a decrease in fuel efficiency, resulting in more frequent trips to the gas station.
• Strange Smells: A damaged catalytic converter can produce a strong sulfur smell, which can be noticeable inside and outside the vehicle.
• Rattling Noise: A damaged catalytic converter can produce a rattling noise, which can be heard from underneath the vehicle.

If you experience any of these symptoms, it is essential to have your vehicle inspected by a qualified mechanic. Ignoring the P0420 code can lead to more severe problems and costly repairs. The mechanic will perform a diagnostic test to determine the cause of the problem and recommend the necessary repairs. In some cases, the catalytic converter may need to be replaced, which can be expensive. However, regular maintenance and timely repairs can help prevent the P0420 code from occurring and ensure your vehicle’s optimal performance and fuel efficiency.

Possible Causes of Mitsubishi P0420 Code

The Mitsubishi P0420 code indicates that the catalyst system’s efficiency is below the threshold for Bank 1. This means that the catalytic converter is not working as efficiently as it should be, resulting in increased emissions. Here are some of the possible causes of this code:

• Faulty Catalytic Converter: The most common cause of the P0420 code is a faulty catalytic converter. Over time, the converter can become clogged or damaged, reducing its efficiency and triggering the code.
• Oxygen Sensor Issues: The oxygen sensors in your vehicle measure the amount of oxygen in the exhaust gases and send this information to the engine control module (ECM). If the sensors are not working correctly, the ECM may not be able to adjust the fuel mixture properly, leading to increased emissions and triggering the P0420 code.
• Exhaust Leaks: Leaks in the exhaust system can cause the P0420 code to appear. If there is a leak before the catalytic converter, it can cause false readings from the oxygen sensors, leading to the code.
• Engine Misfire: A misfiring engine can cause unburned fuel to enter the exhaust system, which can damage the catalytic converter and trigger the P0420 code.
• Fuel System Issues: Problems with the fuel system, such as a clogged fuel injector or a faulty fuel pressure regulator, can cause the engine to run too rich or too lean, leading to increased emissions and triggering the P0420 code.
• Worn Out Spark Plugs: Worn out or fouled spark plugs can cause incomplete combustion, leading to increased emissions and triggering the P0420 code.

In conclusion, the Mitsubishi P0420 code can be caused by a variety of issues, including a faulty catalytic converter, oxygen sensor issues, exhaust leaks, engine misfires, fuel system issues, and worn out spark plugs. If you are experiencing this code, it is important to have your vehicle diagnosed by a qualified mechanic to determine the root cause and make the necessary repairs.

Fixes for Mitsubishi P0420 Code

The P0420 code in Mitsubishi vehicles indicates that the catalyst system’s efficiency is below the threshold for Bank 1. This code is usually caused by a faulty catalytic converter, but there are other possible causes as well. Here are some fixes for the P0420 code:

• Replace the catalytic converter: This is the most common fix for the P0420 code. If the catalytic converter is not working properly, it needs to be replaced. However, before replacing the converter, it’s important to diagnose the root cause of the problem.
• Check the oxygen sensors: The oxygen sensors measure the amount of oxygen in the exhaust system and send this information to the engine control module (ECM). If the sensors are not working properly, they can send incorrect information to the ECM, which can cause the P0420 code. Check the sensors and replace them if necessary.
• Check for exhaust leaks: Exhaust leaks can cause the P0420 code by allowing air to enter the exhaust system, which can affect the readings of the oxygen sensors. Check for leaks and repair them if necessary.
• Clean or replace the mass airflow sensor: The mass airflow sensor measures the amount of air entering the engine and sends this information to the ECM. If the sensor is dirty or faulty, it can cause the P0420 code. Clean or replace the sensor if necessary.
• Check the fuel system: A malfunctioning fuel system can cause the P0420 code by affecting the air/fuel ratio. Check the fuel system and replace any faulty components.
• Reset the ECM: Sometimes, the P0420 code can be triggered by a temporary issue. Resetting the ECM can clear the code and see if it comes back.

In conclusion, the P0420 code in Mitsubishi vehicles can be caused by various factors. The most common fix is to replace the catalytic converter, but it’s important to diagnose the root cause of the problem before replacing any components. Checking the oxygen sensors, exhaust leaks, mass airflow sensor, fuel system, and resetting the ECM are other possible fixes for the P0420 code.

How Much Will it Take to Fix the Mitsubishi P0420 Code?

The cost of fixing the Mitsubishi P0420 code can vary depending on the root cause of the problem. If the issue is a faulty oxygen sensor, the cost can range from $200 to $300. However, if the problem is a damaged catalytic converter, the cost can be significantly higher, ranging from $1,000 to $2,500.

In some cases, the issue may be resolved by simply cleaning the catalytic converter or replacing a damaged exhaust pipe. This can cost anywhere from $100 to $500. However, if the problem is more severe, such as a damaged engine or transmission, the cost can be much higher.

It is important to have the issue diagnosed by a professional mechanic to determine the exact cause of the problem and the cost of repairs. Ignoring the P0420 code can lead to further damage to your vehicle and potentially more expensive repairs in the future.

Possible Causes and Fixes of Mitsubishi P0420 Code

How Serious is the Mitsubishi P0420 Code?

The Mitsubishi P0420 code is a serious issue that needs immediate attention. It indicates that the catalytic converter is not functioning efficiently, which can lead to increased emissions and reduced engine performance. If left unaddressed, it can cause damage to other engine components and result in costly repairs. Additionally, a vehicle with a P0420 code may not pass emissions tests, which can lead to fines and legal issues. Therefore, it is crucial to diagnose and fix the issue as soon as possible to ensure the vehicle’s optimal performance and compliance with environmental regulations.

Can You Still Drive with the Mitsubishi P0420 Code?

Yes, you can still drive with the Mitsubishi P0420 code, but it is not recommended to ignore it for a long time. The code indicates that the catalytic converter is not working efficiently, which can lead to increased emissions and reduced fuel economy. If left unaddressed, it can also cause damage to other engine components.

It is best to have the issue diagnosed and repaired as soon as possible to avoid further damage and potential safety hazards. A qualified mechanic can determine the root cause of the problem and recommend the necessary repairs. In some cases, it may be a simple fix, such as replacing an oxygen sensor, while in other cases, the catalytic converter may need to be replaced.

Conclusion

Dealing with the Mitsubishi P0420 code can be frustrating, but it is important to address it promptly to avoid further damage to your vehicle. The causes of this code can range from a faulty oxygen sensor to a damaged catalytic converter. It is recommended to have a professional mechanic diagnose and repair the issue to ensure proper and safe functioning of your vehicle. Regular maintenance and inspections can also help prevent this code from occurring in the future.

FAQ

What is a P0420 code in Mitsubishi vehicles?

A P0420 code in Mitsubishi vehicles indicates that the catalyst system’s efficiency is below the threshold for Bank 1. This means that the catalytic converter is not working as efficiently as it should be, and it may need to be replaced.

What are the common causes of a P0420 code in Mitsubishi vehicles?

The common causes of a P0420 code in Mitsubishi vehicles include a faulty catalytic converter, oxygen sensor, or exhaust system, engine misfire, fuel system issues, and vacuum leaks. It can also be caused by a software issue in the engine control module.

How can I diagnose a P0420 code in my Mitsubishi vehicle?

To diagnose a P0420 code in your Mitsubishi vehicle, you can use an OBD-II scanner to read the code and check the live data. You can also perform a visual inspection of the exhaust system, check the oxygen sensor readings, and perform a backpressure test on the exhaust system.

Can I still drive my Mitsubishi vehicle with a P0420 code?

It is not recommended to drive your Mitsubishi vehicle with a P0420 code as it can cause further damage to the engine and exhaust system. It can also cause your vehicle to fail an emissions test and result in a fine.

How can I fix a P0420 code in my Mitsubishi vehicle?

The fix for a P0420 code in your Mitsubishi vehicle depends on the underlying cause. It may require replacing the catalytic converter, oxygen sensor, or exhaust system. It may also require repairing any engine misfires, fuel system issues, or vacuum leaks. It is recommended to take your vehicle to a certified mechanic for proper diagnosis and repair.