how to resolve P0301 misfire code in my Toyota Camry Eighth Generation (2018-present)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Ensure the engine is cool before beginning work.

2. Replace Spark Plug

• Remove the engine cover (if applicable) using a socket set.
• Disconnect the ignition coil connector from cylinder 1.
• Remove the bolts securing the ignition coil and lift it out.
• Unscrew the spark plug using a spark plug socket and ratchet.
• Inspect the old spark plug for signs of wear; replace it with a new spark plug (ensure the correct gap and type).
• Reinstall the ignition coil and reconnect the connector.

3. Test and Replace Ignition Coil (if necessary)

• If the ignition coil was swapped during diagnosis and cylinder performance improved, replace the faulty coil with a new one.
• Before installing the new coil, check the connection for corrosion and clean if necessary.
• Install the new ignition coil in cylinder 1 and reconnect.

4. Inspect and Test Fuel Injector

• If the injector is suspected to be faulty, remove the fuel rail (ensure to relieve fuel pressure first).
• Disconnect the fuel injector connector and remove the injector from cylinder 1.
• Test the injector with a multimeter to ensure it is operational; replace with a new injector if faulty.
• Reinstall the fuel rail and reconnect all connectors and hoses.

5. Verify Compression

• If misfire persists, perform a compression test on cylinder 1.
• If compression is low, further investigation into the engine internals may be needed (valve issues, piston rings, etc.).
• Address any mechanical issues identified.