how to fix P0171 code on Toyota Camry Eighth Generation (2018-present)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool before starting work.

2. Inspect and Fix Vacuum Leaks

• Tools Required: Vacuum gauge, flashlight.
• Use a vacuum gauge to check for abnormal readings indicating a leak.
• Visually inspect all vacuum hoses and gaskets for cracks or disconnections.
• Replace any damaged hoses or gaskets as necessary.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, screwdriver.
• Locate the MAF sensor in the air intake duct.
• Disconnect the MAF sensor electrical connector and remove the sensor.
• Spray the MAF sensor with MAF cleaner and allow it to dry completely.
• Reinstall the MAF sensor and reconnect the electrical connector.

4. Check Fuel Pressure

• Tools Required: Fuel pressure gauge.
• Locate the fuel pressure test port on the fuel rail.
• Connect the fuel pressure gauge and turn the ignition to the "ON" position without starting the engine.
• Check that the fuel pressure is within the manufacturer's specifications (usually 30-50 psi).
• If the pressure is low, check the fuel filter and fuel pump for issues. Replace as necessary.

5. Inspect Oxygen Sensors

• Tools Required: O2 sensor socket.
• Locate the upstream oxygen sensor (pre-catalytic converter).
• Disconnect the electrical connector and remove the sensor using the O2 sensor socket.
• Inspect the sensor and replace it if it appears damaged or if the resistance values are out of spec.

6. Clear Codes and Test Drive

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0171 code.
• Start the engine and perform a test drive to ensure that the issue is resolved.