how to fix P0171 code on Honda Civic 10th Generation (2016-2021)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Ensure the engine is cool before beginning work.

Tools Required:

• OBD-II scanner
• Vacuum gauge
• Fuel pressure gauge
• Socket set
• Screwdrivers
• MAF sensor cleaner

2. Inspect and Repair Vacuum Leaks

• Sub-step 1: Visually inspect all vacuum hoses, intake manifold, and gaskets for cracks or disconnections.
• Sub-step 2: Use a vacuum gauge to test for leaks by connecting it to a vacuum source; listen for hissing sounds.
• Sub-step 3: Replace any damaged hoses or gaskets as needed.

3. Clean or Replace MAF Sensor

• Sub-step 1: Locate the MAF sensor on the air intake duct.
• Sub-step 2: Disconnect the electrical connector and carefully remove the sensor.
• Sub-step 3: Clean the MAF sensor with a dedicated MAF cleaner; do not touch the sensor element.
• Sub-step 4: Reinstall the MAF sensor and reconnect the electrical connector.

4. Check Fuel Pressure

• Sub-step 1: Connect a fuel pressure gauge to the fuel rail Schrader valve.
• Sub-step 2: Turn the ignition to the "On" position (do not start the engine) to check the pressure; it should be within manufacturer specifications.
• Sub-step 3: If pressure is low, inspect the fuel pump, fuel filter, and fuel lines for blockages or failures.

5. Inspect and Replace PCV Valve

• Sub-step 1: Locate the PCV valve on the engine (typically on the valve cover).
• Sub-step 2: Remove the PCV valve and shake it; if it rattles, it’s functioning; if not, replace it.
• Sub-step 3: Reinstall the PCV valve, ensuring it is secured properly.