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

Solution

1. Preparation

• Tools Required: Socket set, torque wrench, OBD-II scanner, compression gauge, multimeter, fuel injector cleaner.
• Disconnect the negative battery terminal to ensure safety while working on electrical components.

2. Replace Spark Plug

• Remove the engine cover (if equipped) using a socket set.
• Locate the spark plug for cylinder 2 (refer to the owner's manual for exact location).
• Use a spark plug socket to remove the old spark plug.
• Inspect the spark plug for damage; if it is worn or fouled, replace it with a new spark plug of the recommended type.
• Gap the new spark plug according to manufacturer specifications (usually around 0.043 inches).
• Install the new spark plug and torque it to the manufacturer's specification (typically around 13 lb-ft).

3. Inspect and Replace Ignition Coil

• Disconnect the electrical connector from the ignition coil for cylinder 2.
• Remove the bolts securing the ignition coil and take it out.
• Test the ignition coil's resistance using a multimeter (refer to specifications in the service manual).
• If the coil is faulty, replace it with a new one and reinstall it by reversing the removal steps.

4. Clean or Replace Fuel Injector

• Disconnect the fuel injector connector for cylinder 2.
• Remove the fuel rail if necessary to access the injector (follow the specific steps in the service manual).
• Use a fuel injector cleaner to clean the injector or replace it if it is clogged or malfunctioning.
• Reinstall the injector and the fuel rail, ensuring all connections are secure.

5. Perform Compression Test

• Remove the spark plug from cylinder 2.
• Insert the compression gauge into the spark plug hole.
• Crank the engine a few times and record the compression reading.
• Compare the reading to the manufacturer's specifications; low compression may indicate internal engine problems.

6. Reassemble and Test

• Reconnect all components that were removed during the process.
• Reconnect the negative battery terminal.
• Start the engine and check for any misfire codes.
• Clear the codes using the OBD-II scanner and perform a test drive to ensure the issue is resolved.