what does the P0301 code mean for my Toyota Highlander Fourth Generation (2020-present)

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the negative battery terminal to ensure safety during repairs.

2. Inspect and Replace Spark Plug

• Sub-steps:
  1. Remove the engine cover if necessary.
  2. Locate the ignition coil for cylinder 1 (typically at the front of the engine).
  3. Disconnect the electrical connector from the ignition coil.
  4. Remove the ignition coil using a socket wrench.
  5. Remove the spark plug using a spark plug socket.
  6. Inspect the spark plug for wear or damage; replace if necessary with a new OEM-spec spark plug.
  7. Reinstall the spark plug and torque it to manufacturer specifications (usually around 13-15 ft-lbs).
  8. Reinstall the ignition coil and reconnect the electrical connector.

3. Inspect and Replace Ignition Coil (if necessary)

• Sub-steps:
  1. If the ignition coil appears damaged or faulty, replace it with a new OEM ignition coil.
  2. Ensure proper seating and secure all connections.

4. Check Fuel Delivery

• Sub-steps:
  1. Attach a fuel pressure gauge to the fuel rail's test port.
  2. Start the engine and monitor fuel pressure; it should meet manufacturer's specifications (typically 50-60 psi).
  3. If pressure is low, check the fuel pump and filter for issues.

5. Conduct Compression Test

• Sub-steps:
  1. Remove the spark plug from cylinder 1.
  2. Insert the compression tester into the spark plug hole.
  3. Crank the engine and record the compression reading; it should be within the manufacturer's specified range (usually 150-200 psi).
  4. If compression is low, further investigation of engine internals may be required.