how to diagnose misfire in Honda Accord 9th Generation (2013-2017)

Learn how to diagnose and fix engine misfire issues (P0300-P0306) in Honda Accord 9th Generation (2013-2017). Step-by-step guide with diagnostic procedures.

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool before beginning work.

2. Replace Spark Plugs

• Tools Required: Socket set, torque wrench, gap gauge.
• Remove the ignition coils by unscrewing the retaining bolts and disconnecting the electrical connectors.
• Remove the spark plugs using a spark plug socket.
• Inspect the old spark plugs for signs of wear and ensure the gap is within manufacturer specifications (typically 0.043 inches).
• Install new spark plugs, ensuring the gap is set correctly.
• Torque the spark plugs to the manufacturer's specification (usually around 13 lb-ft).

3. Check/Replace Ignition Coils

• Tools Required: Socket set, multimeter.
• Test each ignition coil for resistance using a multimeter (specifications are usually around 0.5 to 1.5 ohms).
• If any coils are out of spec, replace them with new units.
• Reinstall the ignition coils and reconnect the electrical connectors.

4. Inspect Fuel Delivery System

• Tools Required: Fuel pressure gauge and appropriate fittings.
• Connect the fuel pressure gauge to the fuel rail.
• Start the engine and monitor the fuel pressure; it should be within the manufacturer's specifications (usually around 40-50 psi).
• If the pressure is low, check the fuel pump and fuel filter for proper operation.
• Replace the fuel filter if it is clogged, and consider replacing the fuel pump if necessary.

5. Perform Engine Compression Test

• Tools Required: Compression tester.
• Remove all spark plugs and insert the compression tester into each cylinder.
• Crank the engine and record the compression readings.
• Compare the readings to the manufacturer's specifications; a significant variance may indicate internal engine issues (valves, rings).