how to fix the P0300 code on my Toyota Corolla E170 (2013-2019)?

Solution

1. Preparation

• Gather tools and parts needed for repair.
• Disconnect the negative terminal of the battery to ensure safety.

2. Inspect and Replace Spark Plugs

• Remove the ignition coils by unscrewing the retaining bolts and disconnecting the connectors.
• Remove the spark plugs using a spark plug socket and ratchet.
• Inspect the spark plugs for wear; replace them if they are fouled or worn beyond specifications (replace with OEM specs).
• Reinstall new spark plugs, ensuring they are torqued to the manufacturer’s specifications (typically around 13-15 lb-ft).

3. Check and Replace Ignition Coils (if necessary)

• If the ignition coils show signs of damage or failure during inspection, remove the faulty coils.
• Replace with new OEM ignition coils, ensuring they are seated properly and secured with screws.
• Reconnect the wiring harness to each coil.

4. Fuel System Inspection

• If fuel pressure is low, check the fuel filter and replace if clogged.
• Test the fuel pump operation; replace if it's not providing adequate pressure.

5. Air Intake and Vacuum System

• Inspect the air filter and replace if dirty or clogged.
• Check for any vacuum leaks—replace damaged hoses or components as necessary.

6. Reset Engine Codes

• Reconnect the battery terminal.
• Use the OBD-II scanner to clear the P0300 code from the system.