how to resolve P0171 code on my Honda Civic 9th Generation (2012-2015)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool down before starting work.

2. Inspect and Repair Air Intake System

• Sub-steps:
  • Visually inspect the air intake hoses and clamps for cracks or leaks. Replace any damaged components.
  • Check for loose connections at the throttle body and intake manifold. Tighten as necessary.
  • Use a smoke machine to detect any vacuum leaks if necessary.

3. Fuel System Inspection

• Sub-steps:
  • Connect the fuel pressure gauge to the fuel rail’s Schrader valve; turn the ignition on (do not start the engine) and check the fuel pressure. It should be within manufacturer specifications (typically around 40-50 psi).
  • If the pressure is low, inspect the fuel pump, fuel filter, and fuel lines for blockages or failures. Replace any faulty components.

4. MAF Sensor Cleaning or Replacement

• Sub-steps:
  • Locate the MAF sensor, which is typically found between the air filter and throttle body.
  • Remove the MAF sensor and spray it with MAF sensor cleaner. Allow it to dry completely before reinstalling.
  • If cleaning does not resolve the issue, replace the MAF sensor with a new one.

5. Fuel Injector Service

• Sub-steps:
  • Remove the fuel injectors from the fuel rail, taking care to release any pressure beforehand.
  • Clean the injectors using a specialized cleaning kit or replace them if they are found to be faulty.
  • Reinstall the injectors and ensure they are properly seated and secured.