Bank 2 Air/Fuel Ratio Imbalance
P219B indicates that the engine control module (ECM) has detected an imbalance in the air/fuel ratio between cylinders on Bank 2. This is typically caused by a lean or rich condition in one or more cylinders, often due to vacuum leaks, fuel injector issues, or intake manifold gasket leaks. The ECM monitors oxygen sensor readings and fuel trim values to identify the imbalance.
01. Most Common Causes
- Vacuum leak on Bank 2
- Faulty fuel injector on Bank 2
- Intake manifold gasket leak
- Exhaust leak before oxygen sensor
- Dirty or faulty mass airflow sensor
02. Symptoms You Will Notice
- Check Engine Light on
- Rough idle or misfire
- Poor fuel economy
- Hesitation or stumbling during acceleration
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data.
Step 2: Inspect for vacuum leaks using smoke machine or propane enrichment.
Step 3: Check fuel trim values for Bank 2; compare to Bank 1.
Step 4: Test fuel injectors on Bank 2 for flow and spray pattern.
Step 5: Inspect intake manifold gasket and exhaust system for leaks.
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 the imbalance can cause catalytic converter damage and poor performance.
How much does it cost to fix?▼
Diagnosis typically costs $50-$150, and repairs can range from $100 for a simple vacuum leak fix to $500+ for injector replacement.