Severity High
P02A4

Cylinder 3 Injector Restricted

📅 Last reviewed: July 2026
What does the P02A4 code mean?

The P02A4 code indicates that the engine control module (ECM) has detected a restriction in the fuel injector for cylinder 3. This means the injector is not delivering the correct amount of fuel, often due to clogging or internal damage. The ECM monitors fuel trim and injector performance; when cylinder 3 deviates significantly, this code sets. A restricted injector can cause lean misfires, reduced power, and increased emissions.

High
Severity
$150-$400
Typical Cost
Medium
Frequency

1. Most Common Causes

2. Symptoms You Will Notice

3. Step-by-Step Diagnosis

1

Step 1: Scan for codes and record freeze frame data to confirm P02A4 and check for related codes.

2

Step 2: Perform a fuel injector balance test using a scan tool to compare cylinder 3's contribution against others.

3

Step 3: Visually inspect injector electrical connector and wiring for damage or corrosion.

4

Step 4: If injector is suspected, remove and test it on a flow bench or replace with a known good injector to verify.

4. Frequently Asked Questions

Is it safe to drive with this code?

It is not recommended to drive long distances. A restricted injector can cause misfires, catalytic converter damage, and poor drivability. Have it diagnosed promptly.

How much does it cost to fix?

Replacing a single fuel injector typically costs $150-$400 including parts and labor. Diagnosis may add $50-$100.

5. Commonly Affected Makes

This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.

6. Related Codes

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