how to resolve P0171 code in my Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.

Tools Required:

• OBD-II scanner
• Fuel pressure gauge
• Multimeter
• Socket set
• Torque wrench

2. Inspect and Repair Air Intake System

• Sub-step 1: Visually inspect all vacuum hoses for cracks or disconnections. Replace any damaged hoses.
• Sub-step 2: Check the intake manifold gasket for leaks. If damaged, remove the intake manifold and replace the gasket.
• Sub-step 3: Clean the throttle body using throttle body cleaner and a soft cloth.

3. Test and Replace Components

• Sub-step 1: Connect the fuel pressure gauge to the fuel rail and ensure the pressure is within the manufacturer's specifications (typically around 50-60 psi for most RAV4 models). If low, proceed to the next sub-step.
• Sub-step 2: If low pressure is detected, inspect the fuel pump and filter for clogs or failures. Replace as necessary.
• Sub-step 3: Check the MAF sensor by measuring the voltage output while the engine runs. If out of specification, replace the MAF sensor.

4. Clean or Replace Fuel Injectors

• Sub-step 1: Remove the fuel injectors from the fuel rail. Use an injector cleaning kit to clean them according to the kit instructions.
• Sub-step 2: If cleaning does not resolve the issue, replace the fuel injectors with new ones.

5. Reinstall and Test

• Sub-step 1: Reinstall all components in reverse order of removal, ensuring all connections are secure.
• Sub-step 2: Reconnect the negative battery terminal and clear the error codes using the OBD-II scanner.
• Sub-step 3: Start the engine and monitor for the check engine light.