how to fix P0171 code in Toyota Camry XV40 (2007-2011)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Allow the engine to cool down if it has been running.

2. Inspect and Repair Air Intake System

• Check all vacuum hoses connected to the intake manifold for leaks.
• Replace any cracked or damaged hoses.
• Ensure the air filter is clean; replace if necessary.

3. Clean or Replace MAF Sensor

• Remove the MAF sensor from the air intake duct.
• Use MAF sensor cleaner to clean the sensing element; let it dry completely.
• If cleaning does not resolve the issue, replace the MAF sensor.

4. Check Fuel Pressure

• Connect a fuel pressure gauge to the fuel rail.
• Turn the ignition on (do not start the engine) and check the pressure reading.
• If pressure is below specifications (usually around 40-50 psi), inspect the fuel pump and filter, and replace as necessary.

5. Inspect Fuel Injectors

• Remove the fuel injectors from the engine.
• Clean the injectors using an ultrasonic cleaner or replace them if they are clogged or malfunctioning.

6. Reassemble and Test

• Reinstall all components carefully.
• Reconnect the battery.
• Start the engine and check for any leaks or unusual sounds.