my Tesla Model 3 Highland (2024-present) has a check engine light on for P0301

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, compression tester, vacuum gauge
• Disconnect the negative battery terminal to prevent electrical shorts.
• Allow the engine to cool down before starting work.

2. Inspect and Replace Spark Plug

• Sub-steps:
  • Remove the engine cover (if applicable) using a socket set.
  • Disconnect the ignition coil connector from cylinder 1.
  • Remove the ignition coil using a socket set.
  • Extract the spark plug from cylinder 1 using a spark plug socket.
  • Inspect the spark plug for signs of wear or fouling.
  • Replace with a new spark plug if necessary (ensure gap is set to manufacturer specifications).
  • Reinstall the ignition coil and reconnect the connector.

3. Test and Replace Ignition Coil

• Sub-steps:
  • If the spark plug is fine, test the ignition coil using a multimeter to measure resistance.
  • Replace the ignition coil for cylinder 1 if it does not meet specifications.
  • Reinstall the new ignition coil and reconnect the connector.

4. Inspect and Replace Fuel Injector

• Sub-steps:
  • Disconnect the fuel line to cylinder 1 (be cautious of fuel spray).
  • Remove the injector harness and the fuel injector.
  • Inspect the injector for clogs and test it with a fuel injector tester.
  • Replace the fuel injector if it is not functioning properly.
  • Reinstall the new fuel injector and reconnect the fuel line.

5. Compression Test

• Sub-steps:
  • Remove the spark plug from cylinder 1 after ensuring the ignition is off.
  • Insert the compression tester into the spark plug hole.
  • Crank the engine a few times to get a reading.
  • Compare the reading against manufacturer specifications; replace the cylinder head gasket if the compression is low.