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

Solution

1. Preparation

• Tools Needed: OBD-II scanner, basic hand tools, multimeter, fuel pressure gauge, cleaning supplies for MAF sensor.
• Safety Warning: Disconnect the battery before working on electrical systems. Allow the engine to cool before proceeding.

2. Inspect and Repair Intake System

• Step 1: Inspect the air intake hose and connections for any signs of wear or damage. Replace any damaged hoses.
• Step 2: Check the intake manifold for leaks using a smoke test or propane enrichment method. Repair any leaks found.
• Step 3: Clean the MAF sensor using MAF cleaner spray. Allow it to dry completely before reinstalling.

3. Test and Repair Fuel Delivery Components

• Step 1: Connect a fuel pressure gauge to the fuel rail and turn the ignition on (do not start the engine). Check that the pressure matches the manufacturer's specification.
• Step 2: If pressure is low, inspect the fuel filter and replace if clogged, and check the fuel pump operation. Replace the fuel pump if necessary.

4. Inspect Oxygen Sensors

• Step 1: Using a multimeter, test the voltage output of the upstream oxygen sensor (usually located before the catalytic converter). It should fluctuate between 0.1 to 0.9 volts.
• Step 2: If the sensor is not functioning correctly, replace it according to manufacturer specifications, ensuring to use the correct torque settings during installation.