how to fix P0303 code in Honda Accord 9th Generation (2013-2017)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to ensure safety.

2. Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Unplug the ignition coil connector for cylinder 3.
  3. Remove the ignition coil by unscrewing the mounting bolt and pulling it straight out.
  4. Use a spark plug socket to remove the old spark plug from cylinder 3.
  5. Install the new spark plug, tightening it to the manufacturer's specified torque (typically around 13 lb-ft).
  6. Reinstall the ignition coil and reconnect the wiring harness.

3. Test Ignition Coil

• Sub-steps:
  1. If the spark plug replacement did not resolve the issue, test the ignition coil using a multimeter.
  2. Measure the resistance of the coil; compare it to manufacturer specifications (typically around 0.5 to 2.0 ohms for primary resistance).
  3. Replace the ignition coil if it is out of specification.
  4. Reconnect all electrical connections.

4. Clean or Replace Fuel Injector

• Sub-steps:
  1. If the ignition components are functioning, remove the fuel rail to access the injector for cylinder 3.
  2. Inspect the injector for clogs; clean it using an appropriate fuel injector cleaner or replace it if necessary.
  3. Reinstall the fuel rail and secure it, ensuring all connections are tight.

5. Check Compression

• Sub-steps:
  1. Remove the spark plug for cylinder 3 again.
  2. Insert a compression gauge into the spark plug hole.
  3. Crank the engine and record the compression reading; it should be within the manufacturer's specified range (usually around 170-210 psi).
  4. If compression is low, further engine diagnostics may be necessary (e.g., checking for valve issues or head gasket failure).