how to fix P0302 misfire code on my Toyota Highlander Third Generation (2014-2019)

Solution

1. Preparation

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

2. Replace Spark Plug and Ignition Coil

• Tools Required: Socket set, torque wrench, dielectric grease.
• Remove the engine cover if applicable.
• Disconnect the ignition coil connector from the ignition coil of cylinder 2.
• Remove the bolts securing the ignition coil and carefully pull it out.
• Remove the spark plug using a socket and ratchet.
• Check the spark plug gap; replace it if it is out of specification or worn.
• Install the new spark plug and torque it to the manufacturer's specification (typically around 13 lb-ft).
• Apply dielectric grease to the new ignition coil connector before installation.
• Reinstall the ignition coil and secure it with bolts, then reconnect the ignition coil connector.

3. Inspect and Replace Fuel Injector (if necessary)

• Tools Required: Fuel line disconnect tool, safety glasses, shop towel.
• Relieve fuel pressure in the system by removing the fuel pump fuse and starting the engine until it stalls.
• Disconnect the fuel injector connector and remove the retaining clips.
• Use a fuel line disconnect tool to remove the fuel line from the injector.
• Carefully remove the fuel injector from the rail.
• Inspect the injector for clogs or damage; replace if necessary.
• Install the new fuel injector with a new O-ring and reattach the fuel line and connector.

4. Reassemble and Clear Codes

• Reconnect the negative battery terminal.
• Start the engine and allow it to reach operating temperature.
• Use an OBD-II scanner to clear the P0302 code and any other stored codes.