p0171
Moderate
Toyota · Sedans
System Too Lean Bank 1
Quick Answer
Error code P0171 on your Toyota Sedans means: System Too Lean Bank 1. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
Avalon XLE 2022Camry XSE 2024Camry Hybrid SE 2024Corolla SE 2024Corolla Hybrid LE 2024Crown Platinum 2024Mirai Limited 2024Prius XLE 2024Camry LE 2023Camry LE 2024Camry SE 2023Camry SE 2024Camry TRD 2024Camry XLE 2024Corolla LE 2023Corolla LE 2024Corolla XSE 2024Crown Limited 2024Crown XLE 2024Prius LE 2024Prius Limited 2024
Likely Causes
How to Fix It
1
Inspect intake manifold and vacuum hoses for cracks or disconnections
2
Clean or replace the MAF sensor
3
Check fuel pressure with a gauge and compare to specifications
4
Test fuel injectors for proper spray pattern and flow
5
Inspect exhaust manifold for leaks near the O2 sensor
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
Fuel filter
Fuel injector O-rings
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