my Honda Accord Eleventh Generation (2023-present) has a check engine light and the code is P0301, w...

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, multimeter, vacuum gauge.
• 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

• Remove the ignition coil and spark plug from cylinder one using a socket wrench.
• Inspect the spark plug for wear or fouling. If damaged, replace with a new spark plug (specification: NGK or Denso equivalent).
• Torque the new spark plug to the manufacturer's specifications (typically around 13-16 lb-ft).
• Reinstall the ignition coil, ensuring it clicks into place securely.

3. Test and Replace Ignition Coil (if necessary)

• Use a multimeter to test the resistance of the ignition coil. Compare with the manufacturer’s specifications.
• If out of range, replace the ignition coil with a new one.
• Reconnect the ignition coil after replacement.

4. Inspect Fuel Injector

• Disconnect the electrical connector from the fuel injector and remove it from the engine.
• Check for clogs or debris in the injector. Clean with appropriate fuel injector cleaner or replace if necessary.
• Reinstall the fuel injector and reconnect the electrical connector.

5. Compression Test

• Remove the spark plug from cylinder one and install the compression tester.
• Crank the engine and observe the compression reading. It should be within the manufacturer's specified range.
• If compression is low, further investigation for potential internal engine issues (valve or piston defects) may be required.

6. Check for Vacuum Leaks

• Inspect all vacuum hoses and connections for cracks or damage.
• Use a vacuum gauge to check the intake manifold for leaks. Repair any leaks found.