how to diagnose Honda Pilot Third Generation (2016-present) P0301 misfire code

Solution

1. Preparation

• Gather all necessary tools and parts.
• Disconnect the negative terminal of the battery to ensure safety while working on electrical components.

2. Inspect and Replace Spark Plug

• Tools Required: Socket set (10mm socket), torque wrench, spark plug socket, gap gauge.
• Remove the engine cover (if applicable) by unscrewing bolts.
• Disconnect the ignition coil connector for cylinder 1.
• Unscrew the ignition coil and remove it from the spark plug.
• Using a spark plug socket, remove the spark plug from cylinder 1.
• Inspect the spark plug for wear or damage; replace if necessary.
• Check and adjust the gap of the new spark plug to the manufacturer’s specification (typically 0.043 inches for Honda).
• Install the new spark plug, tightening it to the manufacturer-recommended torque (typically 13 lb-ft).
• Reinstall the ignition coil and reconnect its connector.

3. Inspect and Test Ignition Coil

• If the spark plug replacement does not resolve the issue, test the ignition coil for cylinder 1.
• Tools Required: Multimeter.
• With the ignition coil still disconnected, check the primary and secondary resistance according to the specifications in the service manual.
• If the resistance values are outside the recommended range, replace the ignition coil.

4. Check Fuel Injector

• Remove the fuel injector connector for cylinder 1.
• Tools Required: Noid light or multimeter.
• Use a noid light to check for proper signal at the injector connector while cranking the engine.
• If there is no signal, inspect the wiring and connectors leading to the fuel injector.
• If the signal is present but the injector does not function, replace the fuel injector.

5. Perform Compression Test

• If ignition and fuel systems are confirmed operational, perform a compression test.
• Tools Required: Compression gauge.
• Remove spark plugs from all cylinders.
• Insert the compression gauge into cylinder 1 and crank the engine for a few seconds.
• Compare readings to the manufacturer’s specifications (usually around 190-210 psi for a healthy engine).
• If compression is low, further investigation into engine internals may be required.