how to resolve the P0171 code on my Honda Accord 10th Generation (2018-2022)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Vacuum gauge, hose clamps, socket set
• Inspect all vacuum lines and intake manifold gaskets for cracks or disconnections.
• Use a vacuum gauge to check for leaks; a reading significantly below atmospheric pressure indicates a leak.
• Replace any damaged hoses or gaskets.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, Torx screwdriver
• Locate the MAF sensor in the intake duct.
• Disconnect the electrical connector and remove the sensor using a Torx screwdriver.
• Clean the sensor with MAF cleaner; allow it to dry completely.
• Reinstall the sensor and reconnect the electrical connector.

4. Check Fuel System

• Tools Required: Fuel pressure gauge
• Locate the fuel pressure test port on the fuel rail.
• Connect the fuel pressure gauge and turn the ignition to the "ON" position (do not start the engine) to check fuel pressure.
• Compare the reading to the manufacturer's specifications (typically 40-50 psi for Honda).
• If pressure is low, inspect the fuel pump and replace the fuel filter if necessary.

5. Inspect Fuel Injectors

• Tools Required: Fuel injector cleaner, multimeter
• Disconnect the fuel injector connectors.
• Use a multimeter to check the resistance of each injector; compare readings to specifications.
• If any injector is out of spec, replace the injector.
• Optionally, use a fuel injector cleaner to clean the injectors.

6. Reconnect Battery and Clear Codes

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the P0171 code from the ECM.
• Start the engine and let it warm up to operating temperature.