What is OBD-II Code P2424 – HC Adsorption Catalyst Efficiency Below Threshold Bank 2

HC Adsorption Catalyst Efficiency Below Threshold Bank 2 is a diagnostic trouble code (DTC) that is associated with the OBD-II system in modern cars. When the onboard diagnostic system detects any malfunction inside the engine or exhaust system, it generates an error code similar to P2424. However, this code is pretty complex, and it can be hard for car owners without proper auto mechanic training to understand the problem correctly. In this article, we will explain everything about the P2424 code: its meaning, causes, symptoms, and repairs.

Understanding the P2424 Code

In general, the P2424 code indicates that there is an issue with the Adsorption Catalyst on the Bank 2 side of the engine. Adsorption Catalysts play a crucial role inside the exhaust system in vehicles that use them. They are responsible for converting harmful pollutants from the engine’s exhaust into less harmful substances before they are released into the air. When there is a failure in the Adsorption Catalysts, the OBD-II system detects this and generates the P2424 code. This code indicates that the efficiency of the Adsorption Catalyst on the Bank 2 side of the engine is below the threshold.

What are the Common Causes of the P2424 Code?

The P2424 code has various underlying causes, including:

1. Failed Adsorption Catalyst

The most likely cause of the P2424 code is a failed Adsorption Catalyst. Like most automotive parts, the Adsorption Catalyst can wear out or become damaged over time. This will reduce its efficiency, causing it to fail, and triggering the code.

2. Poor Fuel Quality

Poor fuel quality can cause the Adsorption Catalyst to clog or become contaminated over time. This clogging can reduce its efficiency, causing the P2424 to appear.

3. Damage to Fuel Injector

Fuel injectors are responsible for supplying fuel to the engine. If one of the fuel injectors becomes damaged, it can cause an imbalance in the system, reducing the device’s overall efficiency and triggering the code.

4. Failed Oxygen Sensor

The oxygen sensor is crucial to the exhaust system’s functions in modern vehicles, and when it fails, it can trigger the P2424 code.

What are the Symptoms of the P2424 Code?

The P2424 code may appear on your vehicle’s dashboard as “Check Engine” light. When this happens, you may also experience other symptoms, including:

1. Reduced Fuel Efficiency

When the Adsorption Catalyst becomes damaged or fails, you may find that your vehicle is using more fuel than usual, lowering your gas mileage.

2. Rough Engine Performance

A malfunctioning exhaust system can affect the overall engine performance, causing the car to run roughly or vibrate excessively.

3. Reduced Power Output

You may also experience reduced power output from your vehicle due to the P2424 code.

How to Repair the P2424 Code

Fixing the P2424 code depends on the underlying cause. Some of the common repair methods include:

1. Replacing the Adsorption Catalyst

Replacing the Adsorption Catalyst is the most common repair solution for the P2424 code. This option may be expensive since Adsorption Catalysts can be costly to purchase, but it is the most effective way to restore the engine’s original function.

2. Removing Contamination from the Adsorption Catalyst

If the Adsorption Catalyst is not damaged but contaminated, mechanics can clean it and restore its function.

3. Replacing Damaged Injectors

In some cases, the cause of the P2424 code is a defective fuel injector. In this situation, the damaged injector will need replacing.

4. Replacing Failed Oxygen Sensor

If the oxygen sensor is the cause of the issue, replacing it may remove the P2424 code. This repair is often much more affordable than replacing the Adsorption Catalyst.

Frequently Asked Questions:

1. Can I continue to drive with P2424 Code present on my car?

Yes, you can continue driving your car, but it’s best to consult an auto mechanic and have it repaired as soon as possible.

2. Can I clear the P2424 Code by disconnecting my battery?

Disconnecting your battery may clear the P2424 Code, but it will not fix the underlying issue. The code is likely to appear again until it is fully repaired.

3. How much does it cost to replace the Adsorption Catalyst?

The cost of replacing Adsorption Catalyst varies depending on the make and model of your car. Generally, it ranges from hundreds to thousands of dollars.

4. Can I replace the Adsorption Catalyst by myself?

Replacing the Adsorption Catalyst requires expertise and specialized tools; therefore, it is best left to trained auto mechanics.

5. How long does it take to repair the P2424 Code?

The repair time depends on the underlying cause of the P2424 code. It can vary from a few hours to several days.


The P2424 code represents a complex issue that can significantly impact your vehicle’s functionality. If this code appears, you shouldn’t ignore it, and instead, seek the help of a trained auto mechanic. Remember, your vehicle’s exhaust system and engine operate together, and any issue within the system can cause additional problems if not adequately addressed. A small repair can save you a lot of money in the long run, so don’t hesitate to get the issue looked at.

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