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

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, basic hand tools.
• Disconnect the negative battery terminal to ensure safety during repairs.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 1 by unscrewing the retaining bolts and pulling it off the spark plug.
• Using a socket, remove the spark plug from cylinder 1.
• Inspect the spark plug for wear or damage; replace if necessary with a new spark plug that matches OEM specifications.
• Torque the new spark plug to the manufacturer’s specifications (typically around 13 lb-ft).

3. Inspect and Replace Ignition Coil

• If the spark plug is in good condition but misfire persists, test the ignition coil by inspecting for cracks or damage.
• If the coil is faulty, replace it with a new ignition coil compatible with your Volvo XC90 model.
• Reinstall the ignition coil and ensure it is properly seated.

4. Check and Replace Fuel Injector

• If misfire continues, check the fuel injector for cylinder 1. Disconnect the electrical connector and remove the injector.
• Inspect for clogs or leaks; replace if necessary.
• Reinstall the new or cleaned injector, ensuring proper sealing.

5. Reassemble and Reconnect

• Reconnect all components that were removed during inspection.
• Reconnect the negative battery terminal.