how to fix P0300 code on Toyota Corolla E210 (2019-2024)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal.
• Allow the engine to cool completely before beginning work.

2. Replace Spark Plugs

• Tools Required: Socket set, torque wrench, spark plug socket, dielectric grease.
• Remove the ignition coil by unscrewing it from the cylinder head.
• Unscrew the old spark plug using a spark plug socket and inspect it for wear.
• Install the new spark plug, ensuring it is properly gapped according to manufacturer specifications (typically around 0.043 inches).
• Torque the spark plug to 13 lb-ft (17.6 Nm).
• Apply dielectric grease to the ignition coil boot before reinstallation.

3. Inspect and Replace Ignition Coils (if necessary)

• Tools Required: Socket set, torque wrench.
• Remove the ignition coils from each cylinder by unscrewing them.
• Test the resistance of each coil using a multimeter (consult specifications for acceptable resistance values).
• Replace any faulty ignition coils with new ones.
• Reinstall the ignition coils and torque them to 7 lb-ft (9.5 Nm).

4. Check Fuel Injectors

• Tools Required: Fuel pressure gauge, injector cleaner kit.
• Use a fuel pressure gauge to check the fuel pressure against the manufacturer's specifications.
• If fuel pressure is low, inspect the fuel filter and fuel pump.
• If injectors are suspected to be clogged, use an injector cleaner kit to clean them or replace them if necessary.

5. Inspect Vacuum Hoses

• Tools Required: Visual inspection tools, possible replacement hoses.
• Visually inspect all vacuum hoses for cracks, breaks, or loose connections.
• Replace any damaged hoses to ensure proper vacuum levels.