how to resolve P0301 misfire code on Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

• Gather required tools and parts.
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before working on it.

2. Inspect and Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Remove the ignition coil from cylinder 1 by unbolting and disconnecting the electrical connector.
• Remove the spark plug using a spark plug socket and ratchet.
• Inspect the spark plug for wear, carbon buildup, or damage. If necessary, replace it with a new spark plug (OEM specification).
• Torque the new spark plug to the manufacturer’s specified value (usually around 13-15 lb-ft).

3. Inspect and Replace Ignition Coil

• After replacing the spark plug, visually inspect the ignition coil for cracks or corrosion.
• If the ignition coil appears damaged or has been previously replaced, install a new coil.
• Reconnect the coil to its electrical connector and secure it.

4. Test Fuel Injector

• Tools Required: Fuel injector tester or multimeter.
• Disconnect the fuel injector connector on cylinder 1.
• Use the fuel injector tester to check for proper operation and spray pattern. If the injector is faulty, replace it using appropriate tools.
• Reconnect the injector connector after testing.

5. Check for Vacuum Leaks

• Inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
• Use a smoke machine or carburetor cleaner to identify any leaks around the intake manifold and hoses.
• Replace any damaged hoses or reseal leaks as necessary.

6. Reconnect Battery

• Once all repairs are complete, reconnect the negative battery terminal.