how to diagnose Honda Accord 8th Generation (2008-2012) misfire code P0302

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface, and set the parking brake.
• Disconnect the negative battery terminal to prevent electrical shock.

2. Replace Spark Plug for Cylinder 2

• Tools Required: Spark plug socket, ratchet, torque wrench, dielectric grease.
• Remove the ignition coil from cylinder 2:
  1. Unscrew the mounting bolt(s) securing the coil.
  2. Carefully pull the coil out of the spark plug well.
• Remove the spark plug:
  1. Use the spark plug socket to unscrew the spark plug.
  2. Inspect the spark plug for signs of wear or fouling.
• Install the new spark plug:
  1. Apply a small amount of dielectric grease to the threads.
  2. Hand-tighten the spark plug, then use a torque wrench to tighten to the manufacturer's specification (usually around 13 lb-ft).
• Reinstall the ignition coil:
  1. Align the coil over the spark plug and push it down until it seats.
  2. Secure it with the mounting bolt(s).

3. Test Fuel Injector for Cylinder 2

• Tools Required: Multimeter, noid light or test light.
• Disconnect the fuel injector connector for cylinder 2.
• Use a multimeter to check the resistance of the injector:
  1. Resistance should typically be between 12-16 ohms (refer to specifications).
• If the injector is faulty, replace it:
  1. Remove any retaining clips or screws.
  2. Pull the injector out and install the new one, ensuring a proper seal.

4. Clear Codes and Test Drive

• Reconnect the negative battery terminal.
• Use the OBD-II scanner to clear the fault codes.
• Start the vehicle and monitor for misfires during a test drive.