how to diagnose P0302 code in my Honda Civic 10th Generation (2016-2021)

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the battery to avoid electrical shorts.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 2:
  • Use a socket set to remove the bolts securing the coil.
  • Carefully lift the coil out.
• Remove the spark plug using a spark plug socket:
  • Turn counter-clockwise to loosen and remove the spark plug.
• Inspect the spark plug for damage; replace with a new spark plug if necessary (recommended gap is usually in the range of 0.030 inches).
• Reinstall the new spark plug and ignition coil.

3. Test and Replace Ignition Coil

• Using a multimeter, check the resistance of the ignition coil:
  • Compare readings to manufacturer specifications (typically around 0.5 - 0.6 ohms for primary resistance).
• If the coil is out of specifications, replace it with a new coil.
• Reinstall the ignition coil and secure it with the bolts.

4. Inspect and Replace Fuel Injector

• Disconnect the fuel injector connector and remove the injector:
  • Use a fuel line removal tool if necessary.
• Check for clogs:
  • Clean with a fuel injector cleaning kit or replace it if necessary.
• Reinstall the fuel injector and reconnect the connector.

5. Perform Compression Test

• Remove spark plugs from all cylinders.
• Insert a compression gauge into cylinder 2 and crank the engine:
  • Record the compression reading and compare it to the manufacturer’s specifications (typically around 200 psi).
• If compression is low, further investigate for potential internal engine issues (e.g., valve problems, piston rings).