p0171
Moderate
Ford · Trucks
System Too Lean Bank 1
Quick Answer
Error code P0171 on your Ford Trucks means: System Too Lean Bank 1. This is usually fixable — see the step-by-step guide below.
Affected Models
Applies to all models
F150F150HF150LF150RF250SDF350SDF-150 King Ranch 2024F-150 Lariat 2024F-150 Limited 2024F-150 Platinum 2024F-150 Tremor 2024F-150 XL 2024F-150 XLT 2024F-250 King Ranch 2024F-250 Lariat 2024F-250 XL 2024F-250 XLT 2024F-350 Lariat 2024F-350 Platinum 2024F-350 XL 2024Maverick Lariat 2024Maverick XL 2024Maverick XLT 2024Ranger Lariat 2024Ranger Raptor 2024Ranger XL 2024Ranger XLT 2024MVKRGR
Likely Causes
How to Fix It
1
Inspect intake manifold and vacuum hoses for cracks or disconnections
2
Clean or replace the mass airflow (MAF) sensor
3
Check fuel pressure with a fuel pressure gauge
4
Inspect fuel injectors for clogs and test spray pattern
5
Check for exhaust leaks near the upstream 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 cleaner or replacement MAF sensor
Vacuum hoses
Fuel filter
Fuel injector cleaner
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