📖 What Does P0171 Mean?
The engine is running with too much air and not enough fuel on bank 1. The oxygen sensor is detecting a lean fuel mixture, and the engine control module cannot compensate adequately.
Symptoms
Rough idle, hesitation during acceleration, lack of power, backfiring, hard starting, check engine light, poor fuel economy.
Common Causes
Vacuum leaks, faulty mass airflow sensor, clogged fuel injectors, weak fuel pump, dirty air filter, faulty fuel pressure regulator, intake manifold gasket leak.
Possible Solutions
Find and repair vacuum leaks, clean or replace mass airflow sensor, clean fuel injectors, test and replace fuel pump if needed, replace air filter, check fuel pressure regulator.
Recommended Parts & Tools
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📦 Parts Needed
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Frequently Asked Questions about P0171
How serious is P0171?
This code has a medium severity level. This should be diagnosed and repaired soon to prevent further issues.
Can I drive with P0171?
You can typically drive short distances, but have it diagnosed as soon as possible.
How much does it cost to fix P0171?
Repair costs vary depending on the root cause, but typically range from $100-300 including parts and labor.
Related Diagnostic Codes
Other codes that may appear with P0171
System Too Lean Bank 2
Cylinder 1 Misfire Detected
Cylinder 2 Misfire Detected
Cylinder 3 Misfire Detected
Cylinder 4 Misfire Detected
Catalyst System Efficiency Below Threshold Bank 1
💡 Why These Codes Are Related:
- • Similar Issues: Same root cause or component failure
- • Related Problems: Often occur together due to system interactions
- • Sequential Codes: Progressive failure stages or multiple sensors
- • Same System: Components within the same automotive system