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

Solution

1. Preparation

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

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket, anti-seize compound.
• Remove the ignition coil from cylinder 2 by unbolting it and disconnecting the electrical connector.
• Remove the spark plug using a spark plug socket.
• Inspect the old spark plug for signs of fouling or wear.
• Apply a small amount of anti-seize compound on the threads of the new spark plug.
• Install the new spark plug and torque to the manufacturer’s specification (typically around 13 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Test Ignition Coil

• Tools Required: Multimeter.
• Check the resistance of the ignition coil for cylinder 2 according to specifications (usually around 0.5-0.7 ohms for primary and 10-15 k ohms for secondary).
• If the coil is out of spec, replace it with a new one, ensuring to reconnect all connectors.

4. Inspect Fuel Injector

• Tools Required: Fuel pressure gauge, injector cleaning kit (if needed).
• Check fuel pressure to ensure it meets the manufacturer's specifications (normally 40-50 psi).
• If the pressure is low, inspect the fuel filter and pump.
• Remove the fuel injector from cylinder 2, and clean it using an injector cleaning kit or replace it if necessary.
• Reinstall the fuel injector, ensuring a secure fit.