how to fix P0171 code in Honda CR-V Fifth Generation (2017-2022)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the vehicle's battery to ensure safety.
• Allow the engine to cool before proceeding.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  • Visually inspect all vacuum hoses and the intake manifold for cracks or loose connections.
  • Use a smoke machine or carburetor cleaner to detect leaks while the engine is running.
  • Replace any damaged hoses or reseal the intake manifold if necessary.

3. Clean or Replace the Mass Airflow Sensor (MAF)

• Sub-steps:
  • Locate the MAF sensor between the air filter and throttle body.
  • Disconnect the MAF sensor electrical connector.
  • Remove the MAF sensor using a Torx or Phillips screwdriver.
  • Clean the MAF sensor with MAF cleaner spray and allow it to dry.
  • Reinstall the MAF sensor and reconnect the electrical connector. If damaged, replace it with a new sensor.

4. Check Fuel Pressure

• Sub-steps:
  • Attach a fuel pressure gauge to the fuel rail service port.
  • Turn the ignition to the "ON" position without starting the engine to check the fuel pressure.
  • Compare the reading to the manufacturer specifications (typically around 40-50 psi for Honda).
  • If the pressure is low, inspect the fuel pump, filter, and relay for issues and replace any faulty parts.

5. Inspect Fuel Injectors

• Sub-steps:
  • Remove the fuel rail assembly to access the fuel injectors.
  • Inspect each injector for clogs or leaks.
  • Clean the injectors using a dedicated injector cleaning kit or replace them if necessary.
  • Reassemble the fuel rail and ensure all connections are secure.

6. Check ECT Sensor

• Sub-steps:
  • Locate the ECT sensor near the engine block or thermostat housing.
  • Disconnect the ECT sensor connector and use a multimeter to check the resistance against manufacturer specifications.
  • If resistance is out of spec, replace the ECT sensor.