Question

What does P0171 mean on a Toyota?

P0171 code Toyota means “System Too Lean Bank 1,” implying that the powertrain control module (PCM) has sensed a lean condition on engine’s Bank 1.

The error code in your Toyota car implies a lean air/fuel mixture in a gasoline-powered car’s engine. The PCM triggers the code when it gets signals from the O2 sensors (oxygen sensors), implying a lean air/fuel mixture, i.e., the engine’s combustion chamber has too much air but not enough fuel.

What are the symptoms of Toyota DTC P0171?

The most obvious symptom is the illuminated check engine light. Also, you can observe the following signs.

• Rough idling
• Engine stalling
• Lack of acceleration
• Engine misfiring
• Engine knock
• Hissing sound from the engine bay

What are the possible causes of P0171 in Toyota?

These are reasons why the Toyota P0171 shows up.

• Loose gas cap
• Defective mass airflow (MAF) sensor
• Exhaust leakage
• Blocked fuel filter or injectors
• Weak fuel pump
• Oxygen sensor issues
• Faulty fuel pressure regulator
• Defective Manifold Absolute Pressure (MAP) sensor
• Low fuel pressure
• Defective PCM

How to fix P0171 Toyota

The ideal fix for this error code depends on the exact issue that caused it. The following are some of the standard fixes for this issue.

• Clean or change the mass airflow sensor if it is dirty or blocked.
• If defective, replace the oxygen sensor.
• Repair or change the intake manifold gasket if it is faulty or has a leak.
• Change the fuel filter if the fuel pressure is low.
• Inspect for a vacuum leak. Repair it to stop unmetered air from entering your car’s engine.
• For the right fuel delivery to your car’s engine, clean or replace the dirty or defective fuel injectors.
• At times, you need to update the PCM software to fix the Toyota DTC P0171.

How much does it cost to fix code P0171 in a Toyota?

Depending on the type of repair required, the repair cost of this error code starts at around $150 and may go up to or more than $900.

Is a P0171 code serious for my Toyota?

Yes, it is! We recommend that you don’t drive your car for a long distance with this error code, as it can cause intense engine damage, like burnt valves or melted pistons. So, get your car inspected by a skilled technician and make the required repairs to fix the issue quickly.

What is code P0171 for the Toyota Corolla?

P0171 Toyota Corolla means that the fuel-air mixture has a lean condition, indicating the engine has too much air, but not enough fuel.

What is the code P0171 on a Toyota Camry?

P0171 Toyota Camry​ means that the engine’s Bank 1 has a very lean air-fuel mixture, indicating the engine has too much air but not enough fuel.