how to fix the P0303 code on my Toyota RAV4 XA40 (2013-2018)

Solution

1. Preparation

• Gather necessary tools and parts: OBD-II scanner, socket set, torque wrench, multimeter, compression tester, replacement spark plug, ignition coil, and fuel injector if necessary.
• Disconnect the battery to avoid electrical shorts.

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Locate the spark plug for cylinder 3.
  3. Use a socket wrench to remove the spark plug.
  4. Inspect the spark plug for wear or fouling. Replace if necessary.
  5. Install the new spark plug by hand initially, then torque to manufacturer's specification (typically around 13-16 lb-ft).

3. Inspect and Replace Ignition Coil

• Sub-steps:
  1. Disconnect the electrical connector from the ignition coil on cylinder 3.
  2. Remove the mounting bolts of the ignition coil using a socket wrench.
  3. Remove the ignition coil and inspect for damage.
  4. Install the new ignition coil, ensuring it is seated properly.
  5. Reconnect the electrical connector and secure the ignition coil with its bolts.

4. Inspect and Replace Fuel Injector (if necessary)

• Sub-steps:
  1. Remove the intake manifold if access to the injector is restricted.
  2. Disconnect the electrical connector from the fuel injector on cylinder 3.
  3. Remove the fuel rail bolts and gently pull the rail away to access the injector.
  4. Remove the fuel injector and inspect for clogs or damage.
  5. Install the new fuel injector, ensuring proper sealing.
  6. Reinstall the fuel rail and reconnect all components.

5. Reassemble and Test

• Sub-steps:
  1. Reinstall any components removed (intake manifold, engine cover).
  2. Reconnect the battery.
  3. Start the engine and monitor for smooth operation.