Severity High
P029C

Cylinder 1 Injector Restricted

📅 Last reviewed: July 2026
What does the P029C code mean?

The P029C code indicates that the Engine Control Module (ECM) has detected a restriction in the fuel injector for cylinder 1. This means the injector is not delivering the proper amount of fuel, often due to clogging from debris, carbon buildup, or internal mechanical failure. The ECM monitors fuel trim and injector flow rates to identify this condition.

High
Severity
$50-$150
Typical Cost
High
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.

2

Step 2: Perform a fuel injector balance test to compare cylinder 1 flow to others.

3

Step 3: Inspect fuel injector electrical connector and wiring for damage.

4

Step 4: Check fuel pressure and fuel filter condition.

5

Step 5: If injector is restricted, remove and clean or replace it.

4. Frequently Asked Questions

Is it safe to drive with this code?

It is not recommended to drive long distances as the restriction can cause misfires, catalytic converter damage, and reduced performance. Short trips to a repair shop are okay.

How much does it cost to fix?

The cost typically ranges from $50 to $150 for a single injector cleaning or replacement, plus diagnostic fees. Labor may add $100-$200 depending on vehicle.

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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