p0171
Moderate
Hyundai · Sedans
System Too Lean Bank 1
Quick Answer
Error code P0171 on your Hyundai Sedans means: System Too Lean Bank 1. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
  1. Faulty oxygen sensor
  2. Leaking fuel injector
  3. Damaged fuel pressure regulator
  4. Vacuum leak in intake manifold
  5. Dirty mass airflow sensor
How to Fix It
1
Connect OBD-II scanner and confirm P0171 code
2
Inspect oxygen sensor connectors for damage or corrosion
3
Check fuel pressure using fuel pressure gauge
4
Scan intake system for visible vacuum leaks
5
Clean or replace mass airflow sensor as needed
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Oxygen sensor
Fuel injector
Mass airflow sensor
Intake gasket
Related Error Codes
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