Cylinder 2 Fuel Trim at Max Limit
The P029E code indicates that the engine control module (ECM) has detected that the fuel trim for cylinder 2 has reached its maximum correction limit. This means the ECM is adding as much fuel as possible to compensate for a lean condition in that cylinder. Common causes include a vacuum leak, faulty fuel injector, low fuel pressure, or a mass airflow sensor issue. If left unaddressed, it can lead to poor engine performance, misfires, and potential catalytic converter damage.
01. Most Common Causes
- Vacuum leak near cylinder 2
- Clogged or faulty fuel injector on cylinder 2
- Low fuel pressure (weak pump or clogged filter)
- Mass airflow (MAF) sensor contamination or failure
- Exhaust leak before oxygen sensor
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Rough idle or engine misfire
- Poor acceleration or hesitation
- Decreased fuel economy
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and record freeze frame data.
Step 2: Inspect for vacuum leaks using a smoke machine or propane enrichment.
Step 3: Check fuel pressure and volume; test fuel injector balance on cylinder 2.
Step 4: Clean or test the MAF sensor; inspect intake for restrictions.
Step 5: Perform a compression test on cylinder 2 to rule out mechanical issues.
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 it can cause misfires and damage the catalytic converter. Short trips to a repair shop are acceptable.
How much does it cost to fix?▼
The cost varies depending on the cause. A simple vacuum leak repair may cost $50-$150, while a fuel injector replacement can be $200-$400. Diagnostic fees are typically $100-$150.