how to fix the P0301 misfire code on my Volvo XC90 Second Generation (2015-2024)

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Disconnect the battery to ensure safety while working on the electrical components.
• Allow the engine to cool before starting work.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set, spark plug socket, torque wrench.
• Remove the ignition coil from cylinder 1 by disconnecting the electrical connector and unscrewing the mounting bolt.
• Carefully remove the spark plug using a spark plug socket.
• Inspect the spark plug for wear or carbon buildup. If damaged, replace it with a new one.
• Install the new spark plug, ensuring it is torqued to the manufacturer’s specification (typically around 18 lb-ft).
• Reinstall the ignition coil securely.

3. Test and Replace Ignition Coil (if necessary)

• Tools Required: Multimeter.
• Test the ignition coil for cylinder 1 using a multimeter to check for proper resistance.
• If the ignition coil is faulty, remove it and replace it with a new one.
• Ensure the new ignition coil is properly connected and secured.

4. Inspect and Clean or Replace Fuel Injector

• Tools Required: Fuel injector cleaning kit or replacement injector.
• Access the fuel injector for cylinder 1 by removing any necessary components.
• If cleaning, use a fuel injector cleaning kit to clean the injector.
• If replacement is necessary, disconnect the fuel line and electrical connector, remove the old injector, and install the new one, ensuring it is seated correctly.

5. Perform Compression Test

• Tools Required: Compression tester.
• Remove the spark plug from cylinder 1 and install the compression tester.
• Crank the engine and record the compression reading. Repeat for all cylinders for comparison.
• If compression is low, further investigation of engine internals may be required.