how to fix P0171 code on Toyota Corolla E210 (2019-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool before starting work.

2. Inspect and Repair Air Intake System

• Tools Required: Visually inspect hoses and connections.
• Check the air intake duct for cracks or loose connections. Replace any damaged hoses or clamps.
• Ensure that the air filter is clean and properly seated.

3. Fuel System Inspection

• Tools Required: Fuel pressure gauge.
• Connect the fuel pressure gauge to the fuel rail.
• Start the engine and check the fuel pressure reading against manufacturer specifications (usually around 43-51 psi for a Toyota Corolla). If pressure is low, inspect the fuel pump and filter for issues.
• If the fuel filter is clogged, replace it.

4. Clean the MAF Sensor

• Tools Required: MAF cleaner.
• Carefully remove the MAF sensor from the air intake path.
• Spray the MAF cleaner onto the sensor and allow it to dry completely before reinstalling.

5. Injector Cleaning or Replacement

• Tools Required: Injector cleaning kit or replacement injectors.
• If fuel injectors are dirty, use an injector cleaning kit to clean them according to the manufacturer's instructions.
• If injectors are faulty, replace them with new ones.

6. Reassemble and Test

• Reconnect any hoses or electrical connectors you have worked on.
• Reconnect the negative battery terminal.
• Start the engine and check for any leaks or abnormal noises.