how to fix the P0300 code on my Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool.

2. Replace Spark Plugs

• Remove the engine cover if applicable.
• Use a socket wrench to remove each spark plug.
• Inspect the old spark plugs and replace with new plugs, ensuring the correct gap is set (typically 0.043 inches for most models).
• Torque the new spark plugs to the manufacturer’s specification (usually around 13 lb-ft).

3. Inspect and Replace Ignition Coils

• Disconnect the electrical connectors from the ignition coils.
• Remove the bolts holding the ignition coils in place using a socket wrench.
• Replace any faulty ignition coils with new ones and ensure they are seated properly.
• Reconnect the electrical connectors securely.

4. Check for Vacuum Leaks

• Visually inspect all vacuum hoses and gaskets for cracks or breaks.
• If using a smoke machine, introduce smoke to the intake manifold and observe for leaks.
• Replace any damaged hoses or gaskets as necessary.

5. Test and Replace Fuel Injectors

• Connect a fuel pressure gauge to the fuel rail and ensure the pressure meets manufacturer specifications (usually around 43-50 psi).
• If pressure is low, check the fuel filter and pump.
• If injectors are suspected to be faulty, remove and clean them or replace them with new units.

6. Perform Compression Test

• Remove all spark plugs.
• Insert the compression gauge into the spark plug holes.
• Crank the engine for a few seconds and record the readings for each cylinder. Ensure they are within manufacturer specifications (typically 150-200 psi).
• Address any cylinders with low compression by looking for potential issues (valves, head gasket).