how to troubleshoot P0301 misfire code in Toyota RAV4 Fourth Generation (2013-2018)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, multimeter, fuel injector cleaner.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Replace Spark Plug

1. Remove the engine cover (if applicable) by unscrewing any fasteners.
2. Locate the spark plug for cylinder 1 and remove the ignition coil by unscrewing it from the cylinder head.
3. Using a spark plug socket, remove the old spark plug and inspect it for wear or fouling.
4. Gap the new spark plug to the manufacturer’s specification (typically 0.043 inches for Toyota).
5. Install the new spark plug and torque it to 13 lb-ft.
6. Reinstall the ignition coil and secure it in place.

3. Inspect and Replace Ignition Coil

1. If the spark plug replacement does not resolve the issue, proceed to inspect the ignition coil.
2. Disconnect the electrical connector from the ignition coil.
3. Remove the ignition coil from the cylinder head.
4. Test the ignition coil with a multimeter to check for proper resistance (refer to the service manual for specific values).
5. If faulty, replace the ignition coil with a new one and secure it properly.
6. Reconnect the electrical connector to the ignition coil.

4. Check Fuel Injector

1. If the ignition coil is functioning correctly, remove the fuel injector for cylinder 1.
2. Inspect the injector for clogs or debris. Clean with fuel injector cleaner if necessary.
3. Test the injector's electrical connection with a multimeter to ensure it is receiving power.
4. If the injector is faulty, replace it with a new one and reinstall.

5. Verify Compression

1. If misfire persists, perform a compression test on cylinder 1.
2. Remove the spark plug and attach the compression tester.
3. Crank the engine and record the compression reading. Compare it to specifications (typically around 180 psi).
4. If compression is low, further investigation into the engine’s internal components may be required (e.g., valve seals, piston rings).