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

Solution

1. Preparation

• Tools Required: OBD-II scanner, fuel pressure gauge, multimeter, socket set, cleaning supplies for MAF sensor.
• Safety Warnings: Disconnect the battery before starting any electrical work. Allow engine to cool before working on any components.

2. Inspect and Repair Air Intake System

• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Inspect all air intake hoses for cracks or disconnections; replace any damaged hoses.
  3. Check the intake manifold for leaks using a smoke test or visual inspection.
  4. Tighten any loose clamps and connections.

3. Check and Clean MAF Sensor

• Sub-steps:
  1. Disconnect the MAF sensor electrical connector.
  2. Remove the MAF sensor from the intake duct.
  3. Use MAF sensor cleaner to clean the sensor element; avoid touching it directly.
  4. Reinstall the MAF sensor and reconnect the electrical connector.

4. Test Fuel Pressure

• Sub-steps:
  1. Locate the fuel rail and attach the fuel pressure gauge to the test port.
  2. Turn the ignition to the "ON" position (do not start) and check the pressure reading.
  3. Compare the reading to manufacturer specifications (typically 30-50 psi for many Honda engines).
  4. If the pressure is low, check the fuel pump and filter for issues.

5. Inspect Oxygen Sensors

• Sub-steps:
  1. Locate the upstream oxygen sensor.
  2. Using a multimeter, check the sensor's voltage output (should fluctuate between 0.1 to 0.9 volts).
  3. If the output is steady or outside the range, replace the sensor.
  4. Repeat the process for the downstream oxygen sensor if necessary.