how to fix P0300 code in Toyota Corolla E140 (2006-2013)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool completely before starting work.

2. Inspect and Replace Spark Plugs

• Tools Required: Socket set, spark plug socket, torque wrench.
• Remove the ignition coil connectors and unscrew the ignition coils using the socket set.
• Remove the spark plugs with the spark plug socket.
• Inspect the spark plugs for wear; replace them if they show signs of excessive wear or fouling.
• Install new spark plugs, tightening them to the manufacturer's specified torque (typically around 13-16 lb-ft).
• Reinstall the ignition coils and reconnect the connectors.

3. Inspect and Replace Ignition Coils

• If any ignition coils were found defective during inspection, replace them.
• Tools Required: Socket set, torque wrench.
• Remove the faulty ignition coil(s) by unscrewing their mounting bolts.
• Install new ignition coil(s) and torque them to the specified value (usually around 7-9 lb-ft).

4. Fuel Injector Inspection and Cleaning

• Tools Required: Fuel injector cleaning kit, fuel pressure gauge.
• Check fuel pressure using the gauge; it should be within specification (usually 43-50 psi).
• If pressure is low, inspect the fuel filter and pump.
• Use a fuel injector cleaning kit to clean injectors if they are clogged.
• Reinstall injectors after cleaning, ensuring proper sealing.

5. Check for Vacuum Leaks

• Inspect all vacuum hoses and connections around the intake manifold.
• Use a smoke machine or spray carb cleaner around the hoses to locate leaks.
• Replace any damaged hoses or re-seat any loose connections.