how to resolve the P0300 code in my Toyota RAV4 Fourth Generation (2013-2018)?

Solution

1. Preparation

• Gather tools and parts needed for the repair.
• Disconnect the negative battery terminal to ensure safety.
• Allow the engine to cool down before beginning work.

2. Inspect and Replace Spark Plugs

• Sub-steps:
  1. Remove the engine cover, if applicable.
  2. Disconnect the ignition coil connectors and remove the coils.
  3. Remove the spark plugs using a spark plug socket and ratchet.
  4. Inspect the spark plugs for wear or fouling; replace if necessary.
  5. Gap the new spark plugs to manufacturer specifications.
  6. Install new spark plugs and reattach the ignition coils.

3. Check and Replace Ignition Coils

• Sub-steps:
  1. If misfires persist after spark plug replacement, test each ignition coil using a multimeter.
  2. Replace any faulty ignition coils with new ones.
  3. Reconnect all ignition coil connectors.

4. Inspect Fuel System

• Sub-steps:
  1. Hook up the fuel pressure gauge to the fuel rail.
  2. Turn the ignition to the "On" position without starting the engine and check fuel pressure.
  3. If the pressure is below specifications, inspect and replace the fuel filter or fuel pump as needed.
  4. Ensure that the fuel injectors are operating correctly; clean or replace if necessary.

5. Check for Vacuum Leaks

• Sub-steps:
  1. Visually inspect all vacuum hoses and connections for cracks or disconnections.
  2. Use a smoke machine or carburetor cleaner to check for leaks while the engine is running.
  3. Repair or replace any damaged hoses.

6. Verify Compression

• Sub-steps:
  1. Remove spark plugs again and insert a compression tester into the cylinder.
  2. Crank the engine and record the compression readings for each cylinder.
  3. If compression is low, further investigation into the engine's internal components (valves, piston rings) may be necessary.