how to fix P0301 code on Honda Accord 8th Generation (2008-2012)?

Solution

1. Preparation

• Gather tools: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, fuel injector cleaning kit.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to prevent electrical shock.

2. Replace Spark Plug

• Remove the ignition coil by unscrewing the mounting bolts and disconnecting the electrical connector.
• Remove the spark plug using a spark plug socket and ratchet.
• Inspect the old spark plug; if worn, replace it with a new one (ensure proper gap as per specifications).
• Reinstall the spark plug and torque it to the manufacturer's specifications (typically 13-16 lb-ft).
• Reinstall the ignition coil and reconnect the electrical connector.

3. Test and Replace Ignition Coil (if necessary)

• Use a multimeter to test the ignition coil for primary and secondary resistance. If readings are out of specification, replace the ignition coil.
• Install the new ignition coil and secure it with the mounting bolts.

4. Compression Test

• Remove the spark plug for cylinder 1 and insert the compression tester.
• Crank the engine and observe the compression reading. Compare with manufacturer specifications (typically around 180-220 psi). If low, further investigation is required (valve issues or head gasket failure).

5. Clean or Replace Fuel Injector

• If the injector is suspected to be clogged, use a fuel injector cleaning kit to flush it.
• If cleaning does not resolve the issue, replace the fuel injector for cylinder 1. To replace, disconnect the fuel rail and remove the old injector. Install the new injector and reconnect the fuel rail.