Cylinder 1 Injector Restricted
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 varnish. The ECM monitors fuel trim and injector flow rates; when cylinder 1's contribution is significantly lower than expected, this code sets. A restricted injector can cause misfires, reduced power, and increased emissions.
01. Most Common Causes
- Clogged fuel injector from debris or carbon buildup
- Faulty fuel injector (internal failure)
- Contaminated fuel (water, dirt, or poor quality)
- Fuel filter restriction causing low pressure
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine misfire or rough idle
- Reduced engine power and acceleration
- Poor fuel economy
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Perform a fuel injector balance test using a scan tool to compare cylinder 1 flow to others.
Step 3: Inspect fuel injector electrical connector and wiring for damage.
Step 4: Remove and visually inspect injector for clogging; consider professional cleaning or replacement.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive long distances as a restricted injector can cause misfires, catalytic converter damage, and poor performance. Short trips to a repair shop are acceptable.
How much does it cost to fix?▼
Costs vary from $50 for a cleaning additive to $150 for professional injector cleaning or replacement. Labor may add $100-$200 if replacement is needed.