my Toyota Highlander XU70 (2020-Present) has a check engine light with P0303 code, what does this me...

Solution

1. Preparation

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

Tools Required:

• OBD-II scanner
• Socket set
• Torque wrench
• Compression tester
• Fuel injector tester (optional)
• Multimeter

2. Inspect and Replace Spark Plug

• Remove the ignition coil from cylinder 3.
• Unscrew and remove the spark plug from cylinder 3 using a socket.
• Inspect the spark plug for wear or damage; replace if necessary.
• Install a new spark plug, tightening it to the manufacturer's specified torque (typically 13-15 lb-ft).
• Reinstall the ignition coil securely.

3. Check and Replace Ignition Coil (if necessary)

• If the spark plug is in good condition but the misfire persists, test the ignition coil for proper operation using a multimeter.
• If faulty, remove the ignition coil and replace it with a new one.
• Reconnect the electrical connector for the ignition coil.

4. Fuel Injector Inspection

• If the ignition coil is functioning, check the fuel injector for cylinder 3.
• Remove the fuel injector and inspect it for clogs or damage.
• Replace the fuel injector if there is any obstruction or if it fails the operation test.

5. Compression Test

• Perform a compression test on cylinder 3 to ensure it has adequate compression (typically between 150-200 psi).
• If compression is low, further investigation into piston rings, valves, or head gasket may be needed.