P0171 on TOYOTA COROLLA — System Too Lean Bank 1

Q: "What does P0171 mean on a TOYOTA COROLLA?"

"P0171 indicates: System Too Lean Bank 1. This is a fuel and air metering code. 4 TOYOTA COROLLA owners have reported this to NHTSA."

Q: "What are the most common causes of P0171 on TOYOTA COROLLA?"

"Based on 4 NHTSA reports, the most commonly cited components are: Engine And Engine Cooling, Engine, Vehicle Speed Control,Engine. These percentages are based on the component field in owner complaints."

Q: "Is P0171 serious on my TOYOTA COROLLA?"

"Of 4 NHTSA reports for this code on TOYOTA COROLLA, none involved a crash or fire. However, any diagnostic code should be evaluated by a qualified mechanic."

Q: "What should I do if my TOYOTA COROLLA shows P0171?"

"1) Check for recalls on your VIN at nhtsa.gov/recalls. 2) Get a professional diagnosis — a code alone doesn't identify the exact failed part. 3) Get 2-3 repair estimates to compare."

What P0171 Means on Your TOYOTA COROLLA

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.

4 TOYOTA COROLLA owners have reported this issue to NHTSA across model years 2005-2018. Most reports come from the 2005, 2007 model years.

Real TOYOTA COROLLA Owner Reports

Source: NHTSA Complaints Database

"My 2005 toyota corolla will stall or lose power at random times. it has the engine light on and reports codes p0171 & p2716. this has happened three times in the past 2 weeks. one time i was driving 60 mph on the freeway and was almost hit from behind."

— 2005 TOYOTA COROLLA owner · ENGINE AND ENGINE COOLING · Filed 01/08/2010

"Tl* the contact owns a 2007 toyota corolla. while driving at any speed, the rpms dropped below 1,000 when the vehicle came to a stop. the vehicle shut off and the engine indicator illuminated. the vehicle was restarted and driven to a mechanic."

— 2007 TOYOTA COROLLA owner · ENGINE · Filed 09/10/2015

"Vehicle fails to start. found codes p0606 (ecm/pcm processor error) and p0303 (random misfire) on obd 2 computer. vehicle towed to toyota dealership where they cleaned spark plugs and cylinders due to engine flooding."

— 2011 TOYOTA COROLLA owner · VEHICLE SPEED CONTROL,ENGINE · Filed 11/04/2013

"The contact owns a 2018 Toyota Corolla. The contact stated while attempting to start the vehicle, or upon approaching a stop, the engine sounded very weak, almost as if the vehicle would shut off. The contact stated that the vehicle had shut off previously while driving through a drive thru."

— 2018 TOYOTA COROLLA owner · FUEL SYSTEM, GASOLINE · Filed 01/11/2024

All reports filed by vehicle owners directly with the U.S. Department of Transportation.

📊 Complaint Trend by Model Year

1

'05

1

'07

1

'11

1

'18

Common Causes on TOYOTA COROLLA

Based on NHTSA complaint component analysis for this vehicle.

ENGINE and ENGINE COOLING 25%

ENGINE 25%

VEHICLE SPEED CONTROL,ENGINE 25%

FUEL SYSTEM, GASOLINE 25%

What To Do Next

1
Check for recalls on YOUR VIN
Go to nhtsa.gov/recalls and enter your VIN. If your vehicle is covered, repairs are free.
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.
3
Compare repair quotes
Get 2–3 quotes. Dealer vs. independent shop prices often differ 30–50% for the same repair.

Frequently Asked Questions

What does P0171 mean on a TOYOTA COROLLA? ▾

P0171 indicates: System Too Lean Bank 1. This is a fuel and air metering code. 4 TOYOTA COROLLA owners have reported this to NHTSA.

What are the most common causes of P0171 on TOYOTA COROLLA? ▾

Based on 4 NHTSA reports, the most commonly cited components are: Engine And Engine Cooling, Engine, Vehicle Speed Control,Engine. These percentages are based on the component field in owner complaints.

Is P0171 serious on my TOYOTA COROLLA? ▾

Of 4 NHTSA reports for this code on TOYOTA COROLLA, none involved a crash or fire. However, any diagnostic code should be evaluated by a qualified mechanic.

What should I do if my TOYOTA COROLLA shows P0171? ▾

1) Check for recalls on your VIN at nhtsa.gov/recalls. 2) Get a professional diagnosis — a code alone doesn't identify the exact failed part. 3) Get 2-3 repair estimates to compare.