what does it mean if my Toyota Tacoma N300 (2016-Present) has a P0171 code

Solution

1. Preparation

• Gather tools and materials required for the repair.
• Disconnect the negative terminal of the battery to prevent electrical shock.
• Ensure the engine is cool before beginning work.

2. Inspect and Repair Vacuum Leaks

1. Visual Inspection: Inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
2. Smoke Test: If necessary, perform a smoke test to identify any hidden vacuum leaks.
3. Repair: Replace any damaged hoses or components as needed.

3. Clean or Replace MAF Sensor

1. Remove MAF Sensor: Disconnect the electrical connector and unscrew the MAF sensor from the air intake.
2. Clean the Sensor: Use MAF sensor cleaner to gently clean the sensor element. Avoid touching the sensor with fingers.
3. Reinstall Sensor: Reattach the MAF sensor, ensuring a secure fit.

4. Check and Adjust Fuel Pressure

1. Connect Fuel Pressure Gauge: Attach the fuel pressure gauge to the fuel rail test port.
2. Test Pressure: Start the engine and check fuel pressure against specifications (typically around 40-50 psi).
3. Repair: If pressure is low, inspect and replace the fuel pump or fuel filter as necessary.

5. Inspect Fuel Injectors

1. Remove Fuel Injectors: Detach the fuel rail and carefully remove the injectors.
2. Test Injectors: Use a multimeter to test the resistance of each injector.
3. Clean or Replace: Clean the injectors if they are clogged or replace them if they are faulty.