how to fix a P0301 misfire code in my Toyota RAV4 XA40 (2013-2018)?

Solution

1. Preparation

• Gather tools and parts.
• Ensure the engine is cool and disconnect the negative battery terminal.
• Tools Required: Socket set, torque wrench, multimeter, compression gauge, OBD-II scanner.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1.
• Unscrew and remove the spark plug using a spark plug socket.
• Inspect the spark plug for signs of wear or fouling (replace if necessary).
• Install a new spark plug (gapping per manufacturer specifications).
• Reinstall the ignition coil and ensure it is seated correctly.

3. Test and Replace Ignition Coil (if necessary)

• Use a multimeter to test the resistance of the ignition coil for cylinder 1.
  • Primary resistance: 0.4 to 0.7 ohms.
  • Secondary resistance: 8,000 to 15,000 ohms.
• If readings are out of spec, replace the ignition coil with a new unit.
• Reconnect the ignition coil.

4. Check and Clean Fuel Injector

• Remove the fuel injector for cylinder 1 by disconnecting the electrical connector and unscrewing the retaining clips.
• Inspect the injector for clogs or damage; clean or replace if necessary.
• Reinstall the fuel injector and reconnect the electrical connector.

5. Compression Test

• Remove the spark plug from cylinder 1.
• Insert compression gauge into the spark plug hole.
• Crank the engine and record the compression reading.
• Compare the reading to factory specifications; if low, inspect for internal engine issues.