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

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the battery to ensure safety.
• Ensure the vehicle is on a flat surface and that the engine is cool.

2. Inspect and Replace Spark Plugs

• Remove the ignition coils using a socket set.
• Carefully pull out the spark plugs with a spark plug socket.
• Inspect the spark plugs for signs of wear (e.g., fouling, excessive gap).
• Replace with OEM spark plugs if necessary, torque to manufacturer specifications (typically 13 lb-ft).

3. Test and Replace Ignition Coils

• Remove the ignition coils from the spark plugs.
• Use a multimeter to test the primary and secondary resistance of each coil.
• Replace any faulty ignition coils with OEM parts, torque to specifications (typically 10-12 lb-ft).

4. Inspect and Clean Fuel Injectors

• Remove the fuel rail assembly.
• Disconnect fuel injector connectors and carefully remove fuel injectors.
• Clean the injectors using a suitable injector cleaning kit or replace them if they are clogged.
• Reinstall the fuel injectors and ensure proper seating.

5. Check for Vacuum Leaks

• Inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
• Use a smoke machine to detect leaks; repair or replace any damaged hoses.

6. Verify Engine Compression

• Remove spark plugs and insert a compression gauge into each cylinder.
• Crank the engine and record the compression readings.
• Compare values against manufacturer specifications; replace any components if compression is low.