how to fix P0171 code in Honda Accord 9th Generation (2013-2017)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Tools Required: OBD-II scanner, fuel pressure gauge, multimeter, socket set, torque wrench, MAF cleaner, smoke machine (optional).
• Safety Warnings: Disconnect the battery before working on electrical systems, and allow the engine to cool before inspecting components.

2. Inspect and Repair Air Intake System

• Step 1: Visually inspect all air intake hoses and connections for cracks or damage.
• Step 2: Tighten or replace any loose or damaged hoses.
• Step 3: If a leak is detected, use a smoke machine to identify the exact location and repair as needed.

3. Check and Clean MAF Sensor

• Step 1: Disconnect the MAF sensor harness.
• Step 2: Remove the MAF sensor from the air intake duct.
• Step 3: Clean the sensor using MAF cleaner. Avoid touching the sensor element.
• Step 4: Reinstall the MAF sensor and reconnect the harness.

4. Test Fuel System Pressure

• Step 1: Connect the fuel pressure gauge to the fuel rail test port.
• Step 2: Turn the ignition to the "ON" position (without starting the engine) and check the fuel pressure reading.
• Step 3: Compare the reading to the manufacturer's specifications (typically around 40-50 psi for Honda).
• Step 4: If pressure is low, check the fuel pump operation and replace if necessary.

5. Inspect and Test Oxygen Sensor

• Step 1: Locate the upstream oxygen sensor on the exhaust manifold.
• Step 2: Disconnect the sensor harness and use a multimeter to test for proper voltage output.
• Step 3: If the sensor shows faulty readings, replace it with a new unit.
• Step 4: Reconnect the harness after testing or replacing the sensor.