how to fix P0301 misfire code in my Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

• Gather tools and parts. Ensure the vehicle is parked on a flat surface and the engine is cool.
• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, multimeter, fuel injector cleaner.
• Parts Required: Spark plug, ignition coil, fuel injector (if needed), vacuum hose (if damaged).

2. Replace Spark Plug

1. Disconnect the negative battery terminal to prevent electrical shorts.
2. Remove the engine cover (if applicable) to access the ignition components.
3. Remove the ignition coil by unscrewing it and disconnecting the electrical connector.
4. Unscrew the spark plug using a spark plug socket and inspect it for wear or damage.
5. Install the new spark plug and torque it to the manufacturer's specifications (typically around 13-16 lb-ft).
6. Reinstall the ignition coil and reconnect the electrical connector.

3. Test/Replace Ignition Coil

1. Use a multimeter to test the ignition coil's primary and secondary resistance according to the manufacturer's specifications.
2. If the coil is faulty, remove it as per step 3.1-3.3 above.
3. Install the new ignition coil and ensure it is securely connected.

4. Inspect/Replace Fuel Injector

1. Connect a fuel pressure gauge to the fuel rail to check for proper fuel pressure.
2. If fuel pressure is low, test the fuel injector wiring with a multimeter for continuity.
3. If the injector is faulty, remove it by detaching the fuel rail and unscrewing the injector.
4. Clean the injector using a fuel injector cleaner or replace it with a new one.
5. Reinstall the fuel rail and reconnect all components.

5. Perform Compression Test

1. Remove the spark plug from cylinder 1.
2. Insert a compression tester into the spark plug hole and crank the engine.
3. Record the compression reading and compare it to the manufacturer's specification (usually around 180-200 psi).
4. If compression is low, further investigation into the engine cylinder may be needed.