how to fix the P0301 misfire code on my Toyota RAV4 XA40 (2013-2018)

Solution

1. Preparation

• Gather tools and parts: OBD-II scanner, socket set, torque wrench, compression gauge, and new spark plugs and ignition coil (if necessary).
• Ensure the vehicle is parked on a level surface and the engine is cool.

2. Inspect and Replace Spark Plug

1. Remove the engine cover (if applicable) using a socket wrench.
2. Disconnect the ignition coil connector for cylinder 1.
3. Remove the ignition coil using a socket wrench.
4. Extract the spark plug using a spark plug socket.
5. Inspect the spark plug for damage or excessive wear; replace it if necessary.
6. Install the new spark plug, hand-tightening it first, then torque it to the manufacturer’s specification (typically around 13-16 lb-ft).
7. Reinstall the ignition coil and reconnect the connector.

3. Test Ignition Coil

1. If the spark plug was replaced but the misfire persists, test the ignition coil with a multimeter.
2. Measure the primary and secondary resistance according to manufacturer specifications.
3. If the coil is out of spec, replace it with a new one.

4. Inspect and Replace Fuel Injector (if necessary)

1. If the ignition system checks out, test the fuel injector for cylinder 1.
2. Disconnect the fuel injector connector and remove the injector.
3. Check for any clogs or leaks; clean or replace the injector as needed.
4. Reinstall the injector, ensuring proper sealing, and reconnect the connector.

5. Perform Compression Test

1. Remove the spark plug again to access the cylinder.
2. Insert the compression gauge into the spark plug hole.
3. Crank the engine to record the compression reading. Compare it to the manufacturer's specifications.
4. If compression is low, further diagnosis of the engine internals may be necessary.