how to fix P0301 misfire code on Toyota Highlander Third Generation (2014-2019)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the engine is cool and disconnect the negative battery terminal to avoid electrical shock.

2. Replace Spark Plug

• Remove the engine cover if equipped.
• Using a socket wrench, remove the spark plug from cylinder 1.
• Inspect the removed spark plug for signs of wear or fouling.
• Install a new spark plug (gapping it per manufacturer specifications).
• Torque the new spark plug to 13 lb-ft (17 Nm).

3. Replace Ignition Coil

• Disconnect the electrical connector from the ignition coil on cylinder 1.
• Remove the mounting bolt securing the ignition coil and pull it out.
• Install the new ignition coil into the cylinder head and secure it with the mounting bolt.
• Reconnect the electrical connector.

4. Clean or Replace Fuel Injector

• If the injector is clogged, use a fuel injector cleaner and follow the product instructions.
• If replacement is required, disconnect the fuel injector harness and remove the injector from the fuel rail.
• Install the new fuel injector and reconnect the harness.

5. Reassemble and Reconnect

• Reinstall the engine cover if removed.
• Reconnect the negative battery terminal.