why does my Honda Civic have a check engine light with code P0302

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a flat surface, and the engine is cool.
• Disconnect the negative battery terminal to prevent any electrical shorts.

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Remove the ignition coil and spark plug from cylinder 2 using a socket wrench.
  2. Inspect the spark plug for signs of wear, damage, or excessive carbon buildup. Replace if necessary with a new spark plug (OEM recommended).
  3. Reinstall the spark plug and torque it to the manufacturer's specification (typically around 13-15 lb-ft).
  4. Reattach the ignition coil securely.

3. Check and Replace Fuel Injector

• Sub-steps:
  1. Disconnect the electrical connector from the fuel injector for cylinder 2.
  2. Remove the fuel rail, if necessary, to access the injector.
  3. Inspect the fuel injector for clogs or damage. Clean or replace the injector if necessary.
  4. Reinstall the fuel rail and reconnect the fuel injector.

4. Perform Compression Test

• Sub-steps:
  1. Remove the spark plugs from all cylinders.
  2. Insert a compression gauge into the spark plug hole of cylinder 2.
  3. Crank the engine several times to obtain a reading. Compare the compression value to the manufacturer’s specifications.
  4. If compression is low, further investigation of the engine internals may be required.

5. Check for Vacuum Leaks

• Sub-steps:
  1. Inspect all vacuum hoses connected to the intake manifold for cracks or disconnections.
  2. Use a smoke machine or carb cleaner spray around the intake area while the engine is running to identify any leaks.