how to fix P0303 code in Honda Accord 8th Generation (2008-2012)

Solution

1. Preparation

• Gather all necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to ensure safety.

2. Replace Spark Plug and Ignition Coil

• Tools Required: Socket set, torque wrench, ratchet, and spark plug socket.
• Remove the engine cover if necessary.
• Disconnect the ignition coil connector from cylinder 3.
• Remove the ignition coil by unscrewing the retaining bolts.
• Take out the spark plug using a spark plug socket.
• Sub-steps:
  • Inspect the old spark plug for signs of wear (gap, carbon buildup, etc.).
  • Install a new spark plug (torque to manufacturer specifications, typically around 13 lb-ft).
  • Install the new ignition coil onto the spark plug and secure it with bolts. Reconnect the ignition coil connector.

3. Inspect and Replace Fuel Injector (if necessary)

• Tools Required: Fuel line disconnect tool, socket set, and safety gloves.
• Relieve fuel system pressure by removing the fuel pump fuse and running the engine until it stalls.
• Disconnect the fuel injector connector and the fuel line.
• Remove the fuel injector from the intake manifold.
• Sub-steps:
  • Inspect the injector for clogs or damage.
  • Install a new fuel injector (if required) and reconnect the fuel line and connector. Ensure there are no leaks.

4. Perform Compression Test (if misfire persists)

• Tools Required: Compression gauge, spark plug socket.
• Remove the spark plug from cylinder 3.
• Insert the compression gauge into the spark plug hole.
• Crank the engine and take the reading.
• Sub-steps:
  • Compare readings to specifications (usually around 180 psi).
  • If compression is low, further diagnosis of internal engine components may be required.