how do I fix the P0303 code on my Toyota Highlander XU70 (2020-Present)

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the negative battery terminal to prevent electrical shock.
• Allow the engine to cool before starting work.

2. Inspect and Replace Ignition Components

• Tools Required: Socket set, torque wrench, spark plug socket, screwdriver.
• Sub-steps:
  1. Remove the engine cover if applicable.
  2. Disconnect the ignition coil connector from the coil on cylinder 3.
  3. Unscrew the ignition coil using the socket set and remove it.
  4. Inspect the spark plug for wear or damage, replace if necessary.
  5. Install a new ignition coil and torque it to the manufacturer’s specification (check service manual for exact torque).
  6. Reconnect the ignition coil connector.

3. Check and Replace Fuel Injector

• Tools Required: Fuel line removal tool, injector puller, socket set.
• Sub-steps:
  1. Relieve fuel system pressure by removing the fuel pump fuse and starting the engine until it stalls.
  2. Disconnect the fuel line from the fuel rail using the fuel line removal tool.
  3. Remove the fuel rail bolts and carefully lift the rail to access the injector for cylinder 3.
  4. Remove the old fuel injector and replace it with a new one, ensuring proper seating and connection.
  5. Reassemble the fuel rail and reconnect the fuel line.

4. Compression Test (if necessary)

• Tools Required: Compression tester.
• Sub-steps:
  1. Remove the spark plug from cylinder 3.
  2. Screw the compression tester into the spark plug hole.
  3. Crank the engine for a few seconds and record the pressure reading.
  4. Compare the reading to manufacturer specifications for acceptable compression levels.

5. Final Assembly and Testing

• Reinstall any components that were removed.
• Reconnect the negative battery terminal.
• Start the engine and allow it to reach operating temperature.