What is OBD-II Code P02A4 – Cylinder 3 – Injector Restricted

OBD-II Code P02A4 – Cylinder 3 – Injector Restricted

As a mechanic, I understand how frustrating it can be for car owners when their vehicle displays an OBD-II code. These codes are essential as they indicate an issue in the car’s engine or emissions system, which needs repair. However, for an average person, these codes may seem daunting as they require technical knowledge to understand them. That’s why in this article, we’ll be discussing OBD-II Code P02A4 – Cylinder 3 – Injector Restricted.

P02A4 is an OBD-II code that specifies a problem with the fuel injector in cylinder 3 of the engine. The code indicates that there is a fuel flow restriction in the injector, which leads to poor engine performance. Cylinder 3 is typically the third cylinder from the front of the engine block, located on the driver’s side in most vehicles. This issue can reduce the fuel efficiency of the vehicle and cause a noticeable drop in engine power.

Symptoms of OBD-II Code P02A4

The symptoms of this code vary depending on the severity of the fuel flow restriction in cylinder 3. Some of the noticeable indications that your engine may display include:

1. Stalling engine: If the fuel restriction is severe enough, the engine may stall entirely, making it impossible to restart the car.

2. Rough idle: The engine may shake and produce a rough vibration when idling, which is a symptom of an uneven fuel supply to cylinder 3.

3. Reduced power: You may notice that the car takes longer to accelerate, and it feels like the engine is not operating to its full potential.

4. Check engine light: This code triggers the check engine light to illuminate, which indicates that your car needs immediate attention from a mechanic.

The Possible Causes of OBD-II Code P02A4

The OBD-II code P02A4 is usually caused by a restricted fuel flow in the injector of cylinder 3. This could be due to the following:

1. Clogged fuel injector: Dirt, carbon deposits or debris can accumulate in the fuel injector’s body, causing a blockage.

2. Faulty fuel injector: The fuel injector may have malfunctioned and is not supplying the right amount of fuel in the cylinder, leading to the restriction.

3. Malfunctioning fuel pump: If the fuel pump is not functioning correctly, it may not supply the right pressure to the fuel injector.

4. Fuel filter clogged: A clogged fuel filter can reduce fuel pressure, leading to fuel flow restriction in the injector of cylinder 3.

How to Repair OBD-II Code P02A4

Repairing this code involves identifying and rectifying the cause of the fuel flow restriction. Below are some possible solutions:

Check Fuel Injector Resistance: The fuel injector’s resistance should be checked with a digital multimeter to determine whether it’s in good condition or not. If it’s outside of the acceptable range, then it needs replacement.

Clean the Fuel System: It’s essential to flush the fuel system and clean any debris, dirt, or carbon buildup in the fuel injector body using a fuel system cleaner.

Check Fuel Pressure: Testing the fuel pressure will help determine whether the issue is caused by the fuel injector or the fuel pump. A weak fuel pressure usually indicates a problem with the fuel pump, which will need replacement or repair.

Replace Fuel Filter: A clogged fuel filter is usually the cause of a restricted fuel flow, which leads to cylinder 3 fuel injector reduction.

Frequently Asked Questions (FAQs)

1. What does P02A4 Cylinder 3 Injector Restricted mean?

OBD-II code P02A4 indicates a problem with the fuel injection system in cylinder 3, leading to a restricted fuel flow in the injector, causing engine performance issues.

2. Can I still drive my car with this code?

It’s not recommended as it can cause irreversible damage to your engine, leading to expensive repairs in the long run.

3. How much does it cost to repair OBD-II Code P02A4?

The cost of repair depends on the cause of the issue. The repair can be either as cheap as replacing the fuel filter or as expensive as replacing the fuel injection system.

4. Can I fix the code myself?

No, you’ll need a professional mechanic to diagnose and repair the issue.

5. How long does it take to repair OBD-II Code P02A4?

Repair times can vary depending on the severity of the issue, but it usually takes between 1 to 4 hours for the mechanic to diagnose and repair the issue.


OBD-II code P02A4 can be a headache for any car owner; however, with a professional mechanic’s guidance, it can be fixed. Always check for the symptoms of the code and rectify the issue on time to avoid more considerable future problems. Remember to change your fuel filter regularly, clean your fuel system, and test your fuel injectors and fuel pump frequently to prevent fuel flow restriction in your car’s engine.

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