how to fix P0171 code in Toyota Camry Eighth Generation (2018-present)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before starting any work.

2. Inspect and Repair Air Intake System

• Sub-steps:
  • Remove the engine cover if necessary.
  • Visually inspect the air intake hose for cracks or loose clamps.
  • Tighten any loose clamps and replace any damaged hoses.
  • Check the intake manifold gasket for signs of wear or leaks and replace it if faulty.

3. Test and Clean MAF Sensor

• Sub-steps:
  • Disconnect the electrical connector from the MAF sensor.
  • Remove the MAF sensor from the air intake duct.
  • Use MAF sensor cleaner to spray and clean the sensor element.
  • Allow it to dry completely before reinstalling.

4. Check and Repair Fuel Delivery System

• Sub-steps:
  • Connect a fuel pressure gauge to the fuel rail service port.
  • Turn on the ignition (without starting the engine) to check the fuel pressure; it should meet manufacturer specifications (typically between 50-60 psi).
  • If pressure is low, inspect the fuel pump, fuel filter, and fuel lines for clogs or failures.
  • Replace any faulty components as necessary.

5. Inspect Oxygen Sensors

• Sub-steps:
  • Locate the upstream O2 sensor(s) in the exhaust system.
  • Use a multimeter to test the sensor's voltage output while the engine runs; it should fluctuate between 0.1 to 0.9 volts.
  • If the sensor is unresponsive or out of range, replace it.