how to fix the P0302 misfire code on my Toyota Highlander Fourth Generation (2020-present)

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to prevent electrical shock.
• Allow the engine to cool before proceeding.

2. Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench, compressed air.
• Remove the engine cover if necessary to access the spark plug.
• Use compressed air to clean around the spark plug to prevent debris from entering the cylinder.
• Remove the old spark plug with the spark plug socket and ratchet.
• Check the new spark plug gap against specifications and adjust if necessary.
• Install the new spark plug and torque it to manufacturer specifications (typically 13-15 ft-lbs).

3. Inspect/Replace Ignition Coil

• Tools Required: Ratchet, socket set, torque wrench.
• Remove the ignition coil connector carefully.
• Remove the ignition coil mounting bolts and take out the coil.
• Inspect for cracks or carbon tracking on the coil. Replace if damaged.
• Install the new or inspected ignition coil and torque it to manufacturer specifications.

4. Check Fuel Injector

• Tools Required: Fuel pressure gauge, multimeter (if testing electrical).
• Use a fuel pressure gauge to check that the fuel pressure is within specifications.
• If the injector is suspected to be faulty, remove it and clean or replace it as necessary.
• Reconnect the fuel injector and ensure it clicks into place.

5. Reassemble and Test

• Reattach any components removed during the repair, including the engine cover.
• Reconnect the negative battery terminal.
• Start the engine and allow it to reach operating temperature.