p0171
Moderate
Volkswagen · SUVs
System Too Lean Bank 1
Quick Answer
Error code P0171 on your Volkswagen SUVs means: System Too Lean Bank 1. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
CAID4ID6B25N5N-LWBCRAtlas Cross Sport SE 2024Atlas Cross Sport SEL 2024Atlas Cross Sport SEL R-Line 2024Atlas SE 2024Atlas SEL 2024Atlas SEL Premium R-Line 2024ID.4 Pro 2024ID.4 Pro S 2024ID.4 Pro S Plus 2024ID.4 Standard 2024Taos S 2024Taos SE 2024Taos SEL 2024Tiguan S 2024Tiguan SE 2024Tiguan SEL 2024Tiguan SEL R-Line 2024
Likely Causes
How to Fix It
1
Monitor short-term and long-term fuel trims with a scan tool to confirm lean condition
2
Use a smoke machine to test for vacuum leaks in the intake manifold, turbo piping, and PCV system
3
Remove and clean or replace the MAF sensor; compare readings to factory specifications
4
Test fuel pressure at the fuel rail and compare to the manufacturer specification
5
Inspect PCV valve and crankcase ventilation hoses for cracks or leaks
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
MAF sensor
Vacuum hoses
PCV valve
Fuel filter
Intake manifold gasket
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