how to diagnose P0171 code on Honda Accord 9th Generation (2013-2017)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to ensure safety.
• Raise the vehicle if necessary for access to components.

2. Inspect and Repair Air Intake System

• Sub-steps:
  • Visually inspect all air intake hoses for cracks or disconnections.
  • Replace any damaged hoses with OEM replacements.
  • Ensure that the air filter is clean and replace it if necessary.

3. Clean or Replace MAF Sensor

• Sub-steps:
  • Remove the MAF sensor from the air intake duct using a socket set.
  • Use MAF sensor cleaner to spray and clean the sensor gently.
  • Reinstall the sensor, ensuring it is securely connected.

4. Check and Adjust Fuel Pressure

• Sub-steps:
  • Attach the fuel pressure gauge to the fuel rail.
  • Turn the ignition to the "ON" position without starting the engine and check the fuel pressure.
  • If pressure is low, inspect the fuel pump and fuel filter for issues and replace as necessary.

5. Inspect Fuel Injectors

• Sub-steps:
  • Visually inspect the fuel injectors for any signs of leakage or clogging.
  • Use an injector cleaning kit if needed to clean clogged injectors.
  • Replace any faulty injectors with new ones.

6. Check Engine Vacuum Lines

• Sub-steps:
  • Inspect all vacuum lines for cracks or disconnections.
  • Replace any damaged lines to ensure proper vacuum levels are maintained.

7. Inspect Oxygen Sensors

• Sub-steps:
  • Remove the upstream oxygen sensor using an O2 sensor socket.
  • Test the sensor's resistance with a multimeter to ensure it is within specifications.
  • Replace the sensor if it is found to be faulty.