my Toyota Corolla E170 (2013-2019) has a P0300 code what are the causes

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety while working on electrical components.

2. Inspect and Replace Spark Plugs

1. Remove the engine cover using a socket set.
2. Disconnect the ignition coil connectors.
3. Unscrew and remove the ignition coils from the spark plugs.
4. Remove the spark plugs using a spark plug socket.
5. Inspect the spark plugs for wear; replace with OEM parts if necessary.
6. Install new spark plugs, ensuring to torque them to the manufacturer’s specifications (typically around 13-15 lb-ft).
7. Reinstall the ignition coils and reconnect the connectors.

3. Test and Replace Ignition Coils

1. Use a multimeter to test the resistance of each ignition coil according to specifications.
2. If any coil is out of spec, remove it and replace it with a new one.
3. Reinstall the ignition coils and ensure all connections are secure.

4. Check Fuel System

1. Connect a fuel pressure gauge to the fuel rail to measure the pressure.
2. If the pressure is below specifications, check the fuel pump and replace if faulty.
3. Inspect and replace the fuel filter if it's clogged or dirty.

5. Inspect for Vacuum Leaks

1. Start the engine and listen for hissing sounds indicating a vacuum leak.
2. Use a smoke machine or carburetor cleaner to locate any leaks around the intake manifold.
3. Repair any leaks found, replacing gaskets or hoses as necessary.