p0171
Moderate
Nissan · Sedans
System Too Lean Bank 1
Quick Answer
Error code P0171 on your Nissan Sedans means: System Too Lean Bank 1. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
Likely Causes
How to Fix It
1
Scan the vehicle with OBD-II scanner to confirm code
2
Inspect vacuum hoses for cracks or disconnections
3
Check oxygen sensor operation and replace if faulty
4
Perform fuel pressure test
5
Clean or replace fuel injectors
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 cleaner or replacement fuel injectors
Vacuum hose kit
Fuel filter
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