P0171 on Toyota Highlander
System Too Lean Bank 1
Methodology: Reviewed against the SAE J2012 generic DTC definition and NHTSA owner-complaint patterns, then scoped to Toyota Highlander context without treating complaints as confirmed diagnoses.
Sources: SAE/OBD-II definitions, manufacturer service information, and public reliability reports (including NHTSA where applicable).
- SAE J2012 Diagnostic Trouble Code Definitions — Generic diagnostic trouble code definition reference for P0171.
- NHTSA recalls, complaints, and manufacturer communications — Used to check public owner complaint context, recall status, and safety-related manufacturer communications by VIN or vehicle.
Limits: Guidance is informational and may not match every model-year or revision. Confirm with the official manual and diagnostics before replacing parts. For safety-critical or electrical work, use a qualified technician.
What P0171 Means on Your Toyota Highlander
P0171 is a diagnostic trouble code indicating: System Too Lean Bank 1. This code relates to the fuel and air metering system. The vehicle's computer detected a condition outside normal operating parameters and stored this code.
Real Toyota Highlander Owner Reports
Source: NHTSA Complaints Database
"Vehicle hesitates and sputters upon acceleration, loss of power, and stalls during operation. Trouble codes P0191, P0171, P0174, and P0107B have generated in combination."
"Vehicle check engine turned on to check AWD system after about 2 days when filling with gas the engine wouldn't start and had Low brake power message on dashboard."
All reports filed by vehicle owners directly with the U.S. Department of Transportation.
📊 Complaint Trend by Model Year
Common Causes on Toyota Highlander
Based on NHTSA complaint component analysis for this vehicle.
What To Do Next
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1
Check for recalls on YOUR VIN
Go to nhtsa.gov/recalls and enter your VIN. If your vehicle is covered, repairs are free.
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2
Get a proper diagnosis
A code alone doesn't tell you the exact failed part. A diagnostic at a shop ($50–$150) pinpoints the root cause before you spend money on parts.
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3
Compare repair quotes
Get 2–3 quotes. Dealer vs. independent shop prices often differ 30–50% for the same repair.