how do I fix P0301 code on my Toyota RAV4 Fifth Generation (2019-present)

Solution

1. Preparation

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

2. Inspect and Replace Spark Plug

• Tools Required: Spark plug socket, ratchet, torque wrench.
• Remove the ignition coil from cylinder 1:
  1. Disconnect the ignition coil wiring harness.
  2. Unbolt the coil and lift it out of the cylinder head.
• Remove the spark plug:
  1. Use the spark plug socket to unscrew the old spark plug.
  2. Inspect the old spark plug for wear or fouling.
• Install a new spark plug:
  1. Apply anti-seize compound to the threads of the new spark plug.
  2. Torque it to the manufacturer’s specification (typically around 13-15 lb-ft).
• Reinstall the ignition coil and reconnect the wiring harness.

3. Check and Replace Ignition Coil (if necessary)

• If the ignition coil is found defective during inspection:
  1. Remove the faulty ignition coil.
  2. Install a new ignition coil for cylinder 1, ensuring proper fitment.
  3. Reconnect the ignition coil wiring harness.

4. Inspect Fuel Injector

• If spark plug and ignition coil are in good condition:
  1. Disconnect the fuel injector connector for cylinder 1.
  2. Perform a resistance test on the injector using a multimeter (should match manufacturer specifications).
  3. If faulty, replace the fuel injector:
     • Remove the fuel rail if necessary.
     • Install the new fuel injector and reconnect the harness.

5. Compression Test (if misfire persists)

• Conduct a compression test on cylinder 1:
  1. Remove the spark plug and attach the compression tester.
  2. Crank the engine and record the compression reading.
  3. If compression is low, further diagnose for potential mechanical issues (e.g., valve problems, head gasket failure).