how to fix P0174 code on my Toyota RAV4 Fourth Generation (2013-2018)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative battery terminal to avoid electrical shorts.
• Allow the engine to cool before starting.

2. Inspect and Repair Vacuum Leaks

• Tools Required: Smoke machine or vacuum gauge, basic hand tools.
• Perform a smoke test or use a vacuum gauge to identify any leaks.
• If leaks are found, replace damaged hoses or gaskets as necessary.

3. Clean or Replace MAF Sensor

• Tools Required: MAF sensor cleaner, screwdriver.
• Remove the MAF sensor from the air intake duct using a screwdriver.
• Spray the MAF sensor with MAF cleaner and allow it to dry completely before reinstalling.
• Ensure all connectors are secure.

4. Check Fuel System

• Tools Required: Fuel pressure gauge.
• Connect the fuel pressure gauge to the fuel rail.
• Turn the ignition to the "ON" position (do not start) and check the fuel pressure reading.
• Compare the reading to the manufacturer's specifications (typically between 30-50 psi).
• If pressure is low, check the fuel pump, filter, and relay for functionality.

5. Replace Oxygen Sensor (if necessary)

• Tools Required: O2 sensor socket, ratchet.
• Disconnect the battery again for safety.
• Remove the oxygen sensor from the exhaust system using an O2 sensor socket.
• Install the new oxygen sensor and connect the wiring harness securely.

6. Reassemble and Test

• Reconnect any components that were removed for access.
• Reconnect the negative battery terminal.
• Clear the P0174 code using the OBD-II scanner.