how to fix P0171 lean code in Honda Accord 9th Generation (2013-2017)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to ensure safety while working on electrical components.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
  2. Use a smoke machine or propane torch (with caution) to identify any vacuum leaks around the intake manifold.
  3. Replace any damaged hoses or repair leaks as necessary.
• Tools Required: Vacuum leak detection equipment, hose clamps, replacement hoses.

3. Clean the Mass Air Flow Sensor

• Sub-steps:
  1. Locate the MAF sensor in the air intake duct.
  2. Disconnect the electrical connector and remove the sensor from the duct.
  3. Spray MAF sensor cleaner on the sensor elements. Avoid touching the sensor with fingers.
  4. Allow the sensor to dry completely before reinstalling.
  5. Reinstall the sensor and reconnect the electrical connector.
• Tools Required: MAF sensor cleaner, screwdriver set.

4. Check Fuel Pressure

• Sub-steps:
  1. Locate the fuel pressure test port on the fuel rail.
  2. Connect a fuel pressure gauge to the port.
  3. Turn the ignition key to the "ON" position (do not start the engine) to check for pressure.
  4. Compare the reading to the manufacturer's specifications; it should generally be around 40-50 psi.
  5. If pressure is low, inspect the fuel pump and fuel filter for issues.
• Tools Required: Fuel pressure gauge.

5. Clean the Throttle Body

• Sub-steps:
  1. Remove the air intake duct connected to the throttle body.
  2. Use throttle body cleaner and a soft cloth to clean the throttle plate and surrounding areas.
  3. Ensure the throttle plate operates smoothly without sticking.
  4. Reinstall the air intake duct securely.
• Tools Required: Throttle body cleaner, soft cloth, screwdriver set.

6. Replace Oxygen Sensors (if necessary)

• Sub-steps:
  1. If the oxygen sensors tested faulty, locate and disconnect the upstream (pre-catalytic converter) sensor.
  2. Remove the sensor using an oxygen sensor socket.
  3. Install the new sensor and connect the electrical connector.
  4. Repeat for the downstream sensor if needed.
• Tools Required: Oxygen sensor socket, wrench set.