why does my Toyota Highlander XU70 (2020-Present) keep throwing a P0174 code?

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Ensure the engine is cool before starting work.

2. Inspect and Repair Vacuum Leaks

• Visually check all vacuum lines and gaskets around the intake manifold and throttle body.
• If leaks are found, replace damaged hoses or gaskets.
• Reassemble the intake system ensuring all connections are secure.

3. Clean or Replace MAF Sensor

• Locate the MAF sensor in the intake tract.
• Remove the sensor using a socket set.
• Clean the sensor with MAF cleaner and allow it to dry completely.
• If damaged, replace the MAF sensor with a new one, ensuring correct orientation during installation.

4. Check and Replace Fuel Filter (if necessary)

• Locate the fuel filter and inspect it for clogs.
• If restricted, replace the fuel filter according to manufacturer specifications.
• Ensure the fuel filter is installed in the correct direction.

5. Test Fuel Injectors

• Use a noid light to check the signal to the injectors while cranking the engine.
• If no signal is present, investigate the wiring and ECM.
• If injectors are clogged, clean or replace them as necessary.