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Toyota P0171 Code – System Too Lean Bank 1
Limited
Safe to drive :
Toyota vehicles only
Applies only to :
Not applicable to :
This explanation does NOT apply to Ford, BMW, GM, VW, or other manufacturers.
Medium
Severity level :
When Does This Code Appear on the Vehicles
Toyota P0171 appears when the engine runs lean and fuel economy drops.
What This Code means on the Vehicles
On Toyota vehicles, P0171 indicates Bank 1 is operating with insufficient fuel correction.
Why This is different from a generic OBD2 Code
Toyota engines commonly trigger this due to intake air leaks rather than fuel pump failure.
Common Situations That Trigger This Code
Cracked intake hose; Vacuum leaks; Dirty MAF sensor.
What Will NOT Fix This Code
Replacing oxygen sensors unnecessarily; Replacing catalytic converter.
How to Clear This Code on Vehicles
Repair intake leaks, clean MAF sensor, verify fuel trims.
Related Manufacturer Specific Codes
Toyota P0174; Toyota P0100
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