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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, fuel pressure gauge.
• Disconnect the battery before starting repairs.

2. Replace Spark Plug

• Remove the ignition coil from cylinder 1:
  • Disconnect the electrical connector.
  • Remove the bolts securing the coil and gently pull it out.
• Remove the spark plug:
  • Use a spark plug socket to unscrew the spark plug.
  • Inspect the spark plug for wear or damage; replace if necessary.
• Install a new spark plug:
  • Torque the new spark plug to the manufacturer’s specifications (usually around 13-16 lb-ft).
• Reinstall the ignition coil:
  • Secure it with bolts and reconnect the electrical connector.

3. Inspect and Replace Ignition Coil (if necessary)

• If the ignition coil appears damaged or if replacing the spark plug does not resolve the issue, replace the ignition coil:
  • Follow the same steps as above to remove the old coil.
  • Install the new ignition coil and ensure it is properly seated.

4. Check Fuel Injector

• If the misfire persists, test the fuel injector for cylinder 1:
  • Remove the fuel injector connector and check for voltage with a multimeter.
  • If there is no voltage, check the wiring for continuity.
  • If the injector is faulty, replace it by removing the fuel rail as needed.

5. Compression Test

• If electrical components are functioning correctly, perform a compression test:
  • Remove the spark plug and insert the compression tester.
  • Crank the engine and note the compression reading.
  • If compression is low, further diagnostics may be needed for internal engine issues.