my Toyota RAV4 XA50 (2019-2024) has a check engine light and code P0303, what to do

Solution

1. Preparation

• Gather tools and parts required for the repair.
• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, fuel injector cleaner.
• Safety Warnings: Disconnect the battery before working on electrical systems. Allow the engine to cool before proceeding.

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 3 using a socket.
• Take out the spark plug from cylinder 3 with the appropriate socket.
• Inspect the spark plug for signs of wear (burnt, cracked, or fouled).
• If necessary, replace the spark plug with a new one; torque to manufacturer specifications (usually 13-15 lb-ft).
• Reinstall the ignition coil securely.

3. Test and Replace Ignition Coil

• Test the ignition coil for cylinder 3 using a multimeter (check primary and secondary resistance).
• If the coil is faulty, remove it and replace it with a new one.
• Reconnect the ignition coil and ensure it is seated properly.

4. Inspect and Clean Fuel Injector

• Disconnect the fuel injector connector for cylinder 3.
• Remove the fuel injector using the appropriate tools.
• Inspect the injector for clogs or damage.
• Clean the injector using a fuel injector cleaner or replace it if necessary.
• Reinstall the injector, ensuring it is seated correctly and reconnect the electrical connector.

5. Perform Compression Test

• Remove the spark plug from cylinder 3.
• Insert the compression tester into the spark plug hole.
• Crank the engine to measure the compression and compare it to manufacturer specifications (typically around 180-200 psi).
• If compression is low, diagnose further for potential internal engine issues.