how to fix P0300 code in Toyota Corolla E170 (2013-2019)

Solution

1. Preparation

• Gather tools and parts needed for repair.
• Disconnect the negative terminal of the battery to prevent electrical shock.
• Ensure the engine is cool before starting work.

2. Replace Spark Plugs

• Remove the engine cover if applicable.
• Use a socket wrench to remove the spark plug wires or ignition coils.
• Remove old spark plugs using a spark plug socket; inspect them for condition.
• Install new spark plugs, ensuring they are gapped correctly to manufacturer specifications (typically 0.044 inches).
• Reconnect ignition coils or spark plug wires securely.

3. Inspect and Replace Ignition Coils (if necessary)

• If ignition coils showed signs of damage, remove them from the engine.
• Use a multimeter to test the resistance of the coils (consult service manual for specifications).
• Replace any faulty ignition coils with new ones, ensuring proper seating and connection.

4. Check Fuel System

• Attach a fuel pressure gauge to the fuel rail and turn the ignition to the "ON" position (do not start the engine) to check fuel pressure.
• If pressure is below specifications, inspect and replace the fuel filter or fuel pump as needed.

5. Inspect Vacuum Lines

• Visually check all vacuum hoses for cracks or disconnections.
• Replace any damaged vacuum hoses to ensure proper engine operation.