how to fix P0171 code in Toyota Tacoma N300 (2016-Present)

Solution

1. Preparation

• Gather all tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts during the repair.
• Allow the engine to cool down if it has been running.

2. Inspect and Replace Air Intake Components

1. Inspect Air Filter

   • Remove the air filter cover and inspect the air filter for clogging. Replace if necessary.
   • Tools: Flathead screwdriver or socket set (depending on cover fasteners).

2. Check and Replace Vacuum Hoses

   • Visually inspect all vacuum hoses for cracks or leaks. Replace any damaged hoses.
   • Tools: Pliers (for hose clamps), replacement hoses.

3. Inspect MAF Sensor

   • Remove the MAF sensor from the air intake. Clean the sensor using MAF sensor cleaner and allow it to dry.
   • If damaged, replace the MAF sensor.
   • Tools: Torx or Phillips screwdriver (depending on sensor type), MAF cleaner.

3. Test and Replace Fuel System Components

1. Check Fuel Pressure

   • Connect a fuel pressure gauge to the fuel rail Schrader valve. Ensure the pressure meets the manufacturer's specifications (usually around 50-60 psi).
   • If pressure is low, check the fuel pump and filter.
   • Tools: Fuel pressure gauge.

2. Inspect Fuel Injectors

   • Test each fuel injector for proper operation using an ohmmeter. Replace any injectors that are out of specification.
   • Tools: Multimeter, replacement injectors.

4. Replace ECT Sensor

1. Locate and Remove ECT Sensor

   • Locate the ECT sensor (usually near the thermostat housing). Disconnect the electrical connector and remove the sensor using a socket wrench.
   • Tools: Socket wrench.

2. Install New ECT Sensor

   • Apply a small amount of thread sealant to the new sensor's threads and install it. Reconnect the electrical connector.
   • Torque to the manufacturer’s specifications (typically around 15-20 ft-lbs).

5. Reassemble and Reset Codes

• Reconnect the MAF sensor and air intake components. Ensure all connections are secure.
• Reconnect the negative battery terminal.
• Clear the P0171 code using the OBD-II scanner and start the engine to check for improvements.