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

Solution

1. Preparation

• Gather necessary tools and parts.
• Park the vehicle on a level surface, engage the parking brake, and disconnect the battery.
• Tools Required: OBD-II scanner, multimeter, fuel pressure gauge, socket set, MAF cleaner.

2. Inspect and Repair Air Intake System

• Sub-step 1: Visually inspect all air intake hoses for cracks or disconnections.
• Sub-step 2: Replace any damaged hoses or gaskets as necessary.
• Sub-step 3: Ensure that the air filter is clean and replace it if it is dirty or clogged.

3. Check and Clean MAF Sensor

• Sub-step 1: Locate the MAF sensor in the air intake path.
• Sub-step 2: Disconnect the electrical connector and remove the sensor.
• Sub-step 3: Clean the MAF sensor with MAF cleaner, following the product instructions.
• Sub-step 4: Reinstall the MAF sensor and reconnect the electrical connector.

4. Test Fuel Pressure

• Sub-step 1: Connect the fuel pressure gauge to the fuel rail test port.
• Sub-step 2: Turn the ignition to the ON position (do not start) to check the fuel pressure.
• Sub-step 3: Compare the reading to the manufacturer's specifications; replace the fuel pump if pressure is low.

5. Inspect and Repair Vacuum Leaks

• Sub-step 1: Check all vacuum lines for cracks or disconnections, particularly around the intake manifold and PCV valve.
• Sub-step 2: Replace any damaged vacuum lines.

6. Verify Oxygen Sensor Functionality

• Sub-step 1: Use a multimeter to check the voltage output of the oxygen sensor while the engine is running.
• Sub-step 2: If the oxygen sensor is not functioning within the specified range, replace it.