how to fix P0171 lean code in Honda Accord 10th Generation (2018-2022)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, multimeter, fuel pressure gauge, vacuum gauge.
• Ensure the vehicle is parked on a flat surface and the engine is off.
• Disconnect the negative battery terminal to avoid electrical shorts.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Visually inspect the air intake hoses for cracks or loose connections.
  2. Tighten or replace any damaged hoses or clamps.
  3. Clean the throttle body using throttle body cleaner and a soft cloth to remove any carbon buildup.

3. Check and Clean Mass Air Flow (MAF) Sensor

• Sub-steps:
  1. Locate the MAF sensor along the air intake duct.
  2. Disconnect the electrical connector and remove the sensor using a socket set.
  3. Clean the sensor with MAF cleaner spray; do not touch the sensor element.
  4. Reinstall the sensor and reconnect the electrical connector.

4. Inspect Fuel Delivery System

• Sub-steps:
  1. Connect the fuel pressure gauge to the fuel rail.
  2. Turn the ignition on (do not start the engine) to check the fuel pressure; it should match manufacturer specifications (typically around 40-50 psi).
  3. If pressure is low, inspect and possibly replace the fuel pump or fuel filter.
  4. Check for any fuel leaks around the injectors and fuel lines.

5. Examine Oxygen Sensors

• Sub-steps:
  1. Locate the upstream (pre-catalytic converter) oxygen sensor.
  2. Disconnect the sensor and test it with a multimeter to ensure it is within specified resistance values.
  3. If the sensor is faulty, replace it with a new one.

6. Reassemble and Restore Power

• Sub-steps:
  1. Reconnect any components you removed during inspection.
  2. Reconnect the negative battery terminal.
  3. Clear the P0171 code using the OBD-II scanner.