how to fix P0171 code on Honda Civic 10th Generation (2016-2021)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to ensure safety during work.
• Allow the engine to cool down before starting the repair.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Visually inspect the air intake duct from the air filter to the throttle body for any cracks or loose connections.
  2. Tighten or replace any loose or damaged hoses.
  3. Use a wrench to check the intake manifold gasket for leaks; replace if damaged.

3. Clean or Replace MAF Sensor

• Sub-steps:
  1. Disconnect the electrical connector from the MAF sensor.
  2. Remove the MAF sensor using a Torx or Phillips screwdriver.
  3. Clean the sensor with MAF cleaner spray; allow it to dry completely.
  4. Reinstall the MAF sensor and reconnect the electrical connector.

4. Test Fuel Pressure

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail test port.
  2. Turn the ignition to the "ON" position without starting the engine and observe the pressure reading.
  3. If pressure is below specifications (refer to manufacturer’s specs), consider replacing the fuel pump or checking the fuel filter.

5. Inspect Fuel Injectors

• Sub-steps:
  1. Remove the fuel rail to access the fuel injectors.
  2. Inspect each injector for clogs or deposits; clean or replace as necessary.
  3. Reinstall the fuel rail ensuring all connections are secure.

6. Clear Codes and Test Drive

• Sub-steps:
  1. Use the OBD-II scanner to clear the P0171 code from the system.
  2. Reconnect the negative battery terminal.
  3. Start the engine and monitor for any reoccurrence of the check engine light.

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Fuel pressure gauge
• Screwdrivers (Torx/Phillips)
• MAF cleaner spray
• Basic hand tools

Parts Required:

• Intake manifold gasket (if damaged)
• MAF sensor (if faulty)
• Fuel pump (if pressure is low)

Estimated Repair Time: 2-4 hours

Safety Warnings:

• Disconnect the battery before working on electrical systems.
• Allow the engine to cool before opening any components to avoid burns.