why does my Toyota Corolla E170 (2013-2019) have a P0301 misfire code

Solution

1. Preparation

• Gather tools and parts necessary for the repair.
• Disconnect the battery to ensure safety during the repair process.

2. Replace Spark Plug

1. Remove Engine Cover: If applicable, remove any engine covers to access the spark plugs.
   • Tools: Socket set
2. Remove Spark Plug: Using a spark plug socket, carefully remove the spark plug from cylinder 1.
3. Install New Spark Plug: Gap the new spark plug to manufacturer specifications and install it in cylinder 1.
   • Torque the spark plug to the specified value (typically 13 lb-ft for Corolla).
4. Reinstall Engine Cover: Replace any engine covers that were removed.

3. Replace Ignition Coil

1. Remove Ignition Coil: Disconnect the electrical connector and remove the mounting bolts for the ignition coil in cylinder 1.
   • Tools: Socket set
2. Install New Ignition Coil: Position the new ignition coil and secure it with mounting bolts. Reconnect the electrical connector.

4. Check and Clean Fuel Injector

1. Access Fuel Injector: Depending on access, you may need to remove the intake manifold to reach the fuel injector.
   • Tools: Socket set, torque wrench
2. Remove Fuel Injector: Disconnect the fuel line and electrical connector, then remove the fuel injector from cylinder 1.
3. Clean or Replace Fuel Injector: Clean the injector with appropriate cleaning solution or replace it if it's faulty.
4. Reinstall Fuel Injector: Secure it back in place and reconnect the fuel line and electrical connector.

5. Check for Vacuum Leaks

1. Inspect Hoses and Gaskets: Visually inspect all intake hoses and gaskets for damage or disconnection.
2. Perform Smoke Test (if available): Use a smoke machine to detect any vacuum leaks in the intake system.