Fuel Trim System Stuck Lean (Bank 1)
The P2179 code means the vehicle's onboard diagnostic system has detected: Fuel Trim System Stuck Lean (Bank 1). This is a moderate severity code.
- Keep driving?
- Short distances only
- DIY difficulty
- moderate
- Estimated cost
- $100 - $600 (parts and labor)
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Common Symptoms
- Check Engine Light on
- Engine runs lean on Bank 1
- Rough idle
- Hesitation during acceleration
- Possible lean misfire
Probable Causes (Ranked by Likelihood)
- Vacuum leak on Bank 1 intake side Very High
- Weak fuel pump not maintaining pressure High
- Clogged fuel injector on Bank 1 Moderate
- Faulty mass airflow sensor reading high Low
Step-by-Step Diagnostic Procedure
-
Check for vacuum leaks using smoke test
-
Monitor short-term and long-term fuel trims on scan tool
-
Check fuel pressure at the rail
-
Inspect Bank 1 fuel injectors for proper spray pattern
Frequently Asked Questions
What does P2179 mean?
P2179 indicates: Fuel Trim System Stuck Lean (Bank 1). The ECM has identified an abnormal condition that needs attention.
Can I drive with P2179?
Drive short distances only and schedule repair.
What is the most common fix?
The most common fix depends on the root cause. Start with basic checks like vacuum leaks, sensor conditions, and fluid levels before replacing components.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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