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

Solution

1. Preparation

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

2. Replace Spark Plug

• Tools Required: Socket set, torque wrench, spark plug socket.
• Remove the ignition coil by unbolting it and disconnecting the electrical connector.
• Unscrew the old spark plug from cylinder 1 using a spark plug socket.
• Inspect the old spark plug for signs of wear or fouling.
• Install the new spark plug by hand to avoid cross-threading, then torque it to the manufacturer’s specification (generally around 13-16 ft-lbs).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Replace Ignition Coil (if necessary)

• Tools Required: Socket set, torque wrench.
• If the ignition coil was found faulty, remove it as described above.
• Install the new ignition coil by aligning it with the spark plug and securing it with bolts.
• Reconnect the electrical connector.

4. Check Fuel Injector Function

• Tools Required: Noid light or multimeter.
• If the fuel injector was found faulty, disconnect the fuel injector connector.
• Connect the noid light or multimeter to verify that the injector is receiving a signal.
• If there is no signal, trace back to the ECM or wiring for issues.
• If the injector is faulty, remove and replace it according to the manufacturer’s instructions.

5. Conduct Compression Test

• Tools Required: Compression tester.
• Remove the spark plug from cylinder 1 and insert the compression tester.
• Crank the engine several times and record the compression reading.
• Compare it against the manufacturer’s specifications (usually around 150 psi).
• If the compression is low, further engine disassembly may be required to diagnose internal issues.