how to fix P0171 code on my Honda Pilot YF3 (2016-2022)

Solution

1. Preparation

• Gather tools: OBD-II scanner, screwdriver set, multimeter, vacuum gauge, and safety glasses.
• Disconnect the negative battery terminal to ensure safety during repairs.

2. Inspect and Repair Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum hoses and connections for cracks or disconnections.
  2. Use a vacuum gauge to test for leaks in the intake manifold and hoses.
  3. If leaks are found, replace the damaged hoses or reattach loose connections.

3. Clean or Replace the MAF Sensor

• Sub-steps:
  1. Locate the MAF sensor in the air intake system.
  2. Disconnect the electrical connector and remove the sensor from the housing.
  3. Clean the MAF sensor with MAF sensor cleaner spray. Avoid touching the sensor element.
  4. If cleaning does not resolve the issue, replace the MAF sensor with a new one.

4. Check Fuel System

• Sub-steps:
  1. Inspect the fuel filter for blockages and replace if necessary.
  2. Use a fuel pressure gauge to check for proper fuel pressure. Compare readings to manufacturer specifications.
  3. If fuel pressure is low, check the fuel pump and relay, replacing them if faulty.

5. Inspect Oxygen Sensors

• Sub-steps:
  1. Locate the upstream and downstream oxygen sensors.
  2. Use a multimeter to test the voltage output of the upstream sensor while the engine is running.
  3. If the voltage is consistently low or not fluctuating, replace the oxygen sensor.