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

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Ensure the vehicle is parked on a flat surface, and the engine is cool.
• Disconnect the negative battery cable to prevent electrical shorts.

2. Inspect and Repair Air Intake System

• 1.1 Visually inspect the air intake duct for cracks or loose connections.
• 1.2 Check all vacuum hoses connected to the intake manifold for any signs of wear or damage. Replace any defective hoses.
• 1.3 Tighten any loose clamps and ensure all connections are secure.

3. Fuel System Checks

• 2.1 Connect a fuel pressure gauge to the fuel rail.
• 2.2 Turn the ignition on (without starting the engine) and check the fuel pressure reading; it should meet manufacturer specifications (typically around 40-50 PSI).
• 2.3 If pressure is low, check the fuel pump and filter for clogs or malfunctions, replacing as necessary.

4. MAF Sensor Cleaning/Replacement

• 3.1 Locate the mass air flow sensor in the air intake path.
• 3.2 Disconnect the electrical connector and remove the MAF sensor from its housing.
• 3.3 Clean the sensor using MAF cleaner spray (do not use any other types of cleaners).
• 3.4 Reinstall the MAF sensor and reconnect the electrical connector.

5. Oxygen Sensor Check

• 4.1 Locate the upstream oxygen sensor (before the catalytic converter).
• 4.2 Disconnect the sensor and test its resistance with a multimeter according to specifications.
• 4.3 Replace the oxygen sensor if it is out of specification.

6. Reconnect Battery and Clear Codes

• 5.1 Reconnect the negative battery cable.
• 5.2 Use the OBD-II scanner to clear the P0171 code.
• 5.3 Start the engine and allow it to reach operating temperature.