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

Solution

1. Preparation

• Tools Required: OBD-II scanner, multimeter, vacuum gauge, fuel pressure gauge, socket set, screwdriver set, cleaning supplies (MAF cleaner, rags).
• Safety Warnings: Disconnect the battery before starting work on electrical components.

2. Inspect and Repair Intake System

1. Check for Vacuum Leaks

   • Visually inspect all vacuum hoses and connections.
   • Use a vacuum gauge to test for leaks; a reading below normal indicates a leak.
   • Repair or replace any damaged hoses or fittings.

2. Examine Throttle Body and Intake Manifold

   • Remove the air intake duct to access the throttle body.
   • Clean the throttle body using throttle body cleaner and a soft brush.
   • Ensure the intake manifold is properly sealed and free of cracks.

3. Clean or Replace MAF Sensor

1. Remove MAF Sensor

   • Disconnect the electrical connector and unscrew the MAF sensor from the air intake.

2. Clean MAF Sensor

   • Spray MAF sensor cleaner onto the sensor elements (do not touch them).
   • Allow it to dry completely before reinstalling.

3. Reinstall MAF Sensor

   • Reattach the MAF sensor and ensure a tight fit.

4. Check Fuel System

1. Test Fuel Pressure

   • Connect a fuel pressure gauge to the fuel rail.
   • Turn the ignition to the "ON" position without starting to check initial pressure.
   • Compare the reading to the manufacturer’s specifications; replace the fuel pump if pressure is low.

2. Inspect Fuel Injectors

   • Remove and visually inspect the fuel injectors for clogs or leaks.
   • Clean injectors using an injector cleaning kit or replace them if necessary.

5. Check Oxygen Sensors

1. Inspect Oxygen Sensors
   • Check for any exhaust leaks before the upstream O2 sensor, which can cause lean conditions.
   • Use a multimeter to test the response of the oxygen sensors, replacing any that are out of specification.