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

Solution

1. Preparation

• Tools Required: OBD-II scanner, fuel pressure gauge, multimeter, socket set, torque wrench, MAF sensor cleaner, cleaning cloths, vacuum gauge.
• Ensure the vehicle is parked on a level surface, the engine is cool, and the battery is disconnected before starting any work.

2. Inspect and Repair Air Intake System

• Inspect all air intake hoses and connections for cracks or loose fittings.
• Tighten any loose clamps or replace damaged hoses.
• If a leak is found, replace the affected component.

3. Clean or Replace MAF Sensor

• Remove the MAF sensor from the air intake duct by unscrewing it carefully.
• Spray MAF sensor cleaner on the sensor element; do not touch the element directly.
• Allow it to dry completely before reinstalling.
• If the sensor is damaged or cleaning does not resolve the issue, replace it with a new unit.

4. Check and Adjust Fuel Pressure

• Connect the fuel pressure gauge to the fuel rail service port.
• Turn the ignition to the "ON" position (without starting the engine) and check the pressure.
• Compare the reading to the manufacturer’s specifications (typically between 40-50 psi). If the pressure is low, check the fuel pump and fuel filter for blockages or failures.
• Replace the fuel pump or filter if necessary.

5. Inspect and Clean Throttle Body

• Remove the throttle body from the intake manifold by unscrewing it.
• Use throttle body cleaner and a cleaning cloth to remove carbon deposits from the throttle plate and inside the housing.
• Reinstall the throttle body and ensure it’s properly torqued to manufacturer specifications.

6. Verify Fuel Injector Functionality

• Using a noid light, connect it to the fuel injector connector to check for signal.
• If there is no signal, inspect wiring and connectors for damage; repair as necessary.
• If injectors are clogged, consider using a fuel injector cleaner additive or removing and cleaning them.