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

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Inspect and Replace Ignition Components

• 1.1 Remove Engine Cover
  • Use a socket set to remove any bolts securing the engine cover.
• 1.2 Check Spark Plugs
  • Remove spark plugs using a spark plug socket.
  • Inspect for wear, fouling, or damage; replace with OEM or equivalent spark plugs if necessary.
• 1.3 Inspect Ignition Coils
  • Remove ignition coils by unfastening bolts and disconnecting electrical connectors.
  • Inspect for cracks or damage; replace faulty coils as needed.

3. Check Fuel System

• 3.1 Verify Fuel Pressure
  • Connect a fuel pressure gauge to the fuel rail test port.
  • Start the engine and monitor the pressure; it should match the manufacturer's specifications (typically 43-50 psi).
• 3.2 Replace Fuel Filter
  • If the fuel pressure is low, replace the fuel filter according to the manufacturer’s guidelines.

4. Inspect Air Intake and Exhaust

• 4.1 Check for Air Leaks
  • Inspect hoses and connections in the air intake system for cracks or loose fittings.
  • Replace any damaged components.
• 4.2 Examine Exhaust System
  • Look for any signs of blockage or damage in the exhaust manifold and catalytic converter.
  • Replace any damaged exhaust components.

5. Final Steps

• Reconnect all components, ensuring everything is secure.
• Reconnect the negative battery terminal.
• Clear the error codes using the OBD-II scanner.