what does it mean when my Toyota Camry has a P0171 code?

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down if it has been running.

2. Inspect and Repair Air Intake System

• Tools Required: Socket set, screwdrivers, vacuum gauge.
• Check all hoses and connections for cracks or loose fittings.
  1. Remove the air intake duct and inspect the MAF sensor.
  2. Clean the MAF sensor with MAF cleaner if contaminated.
  3. Reinstall the air intake duct ensuring a tight fit.

3. Test and Repair Fuel System

• Tools Required: Fuel pressure gauge, socket set.
• Check the fuel pressure at the fuel rail.
  1. Connect the fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the ON position (do not start) and note the pressure.
  3. If pressure is low, check the fuel pump and replace the fuel filter if clogged.

4. Inspect Oxygen Sensors

• Tools Required: O2 sensor socket, multimeter.
• Check the functionality of the upstream oxygen sensor.
  1. Remove the oxygen sensor using the O2 sensor socket.
  2. Test the sensor's voltage output with a multimeter.
  3. Replace the sensor if it is out of specification.