how to fix P0301 misfire code in Volvo XC90 Second Generation (2015-2024)?

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Inspect and Replace Spark Plug

• Tools Required: Spark plug socket, torque wrench, gap gauge.
• Remove the ignition coil cover if applicable.
• Disconnect the wiring harness from the ignition coil.
• Remove the ignition coil from cylinder 1.
• Unscrew the spark plug using the spark plug socket.
• Inspect the spark plug condition; replace if worn or damaged.
• Set the gap on the new spark plug to the manufacturer's specification.
• Install the new spark plug and torque to the manufacturer’s specifications (typically around 13-18 lb-ft).
• Reinstall the ignition coil and reconnect the wiring harness.

3. Test and Replace Ignition Coil (if necessary)

• If the ignition coil appears damaged during inspection, replace it.
• Remove the ignition coil from cylinder 1.
• Install a new ignition coil, ensuring it properly seats on the spark plug.
• Reconnect the wiring harness.

4. Inspect Fuel Injector

• Disconnect the fuel injector connector.
• Use a multimeter to test the injector's resistance; compare to manufacturer specifications.
• If faulty, replace the fuel injector by removing it from the rail and installing a new one.
• Reconnect the fuel injector connector.

5. Verify and Reassemble

• Reconnect the negative battery terminal.
• Clear the trouble codes using the OBD-II scanner.
• Start the engine and observe for any misfires or check engine light.