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

Solution

1. Preparation

• Tools Required: OBD-II scanner, fuel pressure gauge, MAF sensor cleaner, basic hand tools (sockets, wrenches), torque wrench, vacuum gauge.
• Safety Warnings: Disconnect the battery before working on electrical systems to prevent short circuits.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Visually inspect all air intake hoses and clamps for cracks or loose fittings.
  2. Tighten any loose connections and replace any damaged hoses.
  3. Ensure the air filter is clean and not obstructed; replace if necessary.

3. Check and Clean MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the air intake duct.
  2. Disconnect the electrical connector from the MAF sensor.
  3. Remove the MAF sensor from the duct by loosening the securing screws.
  4. Clean the sensor using MAF sensor cleaner and let it dry completely before reinstalling.
  5. Reinstall the MAF sensor and reconnect the electrical connector.

4. Test Fuel Pressure

• Sub-steps:
  1. Locate the fuel pressure test port on the fuel rail.
  2. Attach the fuel pressure gauge to the test port securely.
  3. Turn the ignition to the "On" position (without starting the engine) to check the pressure.
  4. Compare the reading to manufacturer specifications; if low, inspect the fuel pump and filter for issues.
  5. If pressure is low, replace the fuel filter and/or fuel pump as necessary.

5. Inspect Fuel Injectors

• Sub-steps:
  1. Locate the fuel injector rail and disconnect the fuel lines (use caution as fuel may leak).
  2. Remove the fuel injectors from the rail.
  3. Inspect each injector for clogs or leaks and clean or replace as needed.
  4. Reinstall the injectors and reconnect the fuel lines securely.

6. Check Engine Coolant Temperature (ECT) Sensor

• Sub-steps:
  1. Locate the ECT sensor on the engine (usually near the thermostat housing).
  2. Disconnect the electrical connector from the sensor.
  3. Use a multimeter to check the resistance of the sensor; compare to specifications from the service manual.
  4. Replace the ECT sensor if readings are out of range.