how to diagnose a misfire in my Toyota RAV4 Fourth Generation (2013-2018)

Solution

1. Preparation

• Tools Required: OBD-II scanner, socket set, torque wrench, multimeter, fuel pressure gauge.
• Disconnect the negative battery terminal to prevent electrical shorts.

2. Replace Spark Plugs

• Remove the engine cover if necessary.
• Use the socket set to remove the ignition coils.
• Remove old spark plugs using a spark plug socket.
• Inspect the gap on new spark plugs and ensure it matches the manufacturer's specifications.
• Install new spark plugs and torque them to manufacturer specifications (typically around 13-18 lb-ft).
• Reinstall ignition coils and secure them.

3. Inspect and Replace Ignition Coils (if necessary)

• If misfire codes indicate a specific cylinder, test the ignition coil for that cylinder using a multimeter.
• If faulty, remove the ignition coil from the engine.
• Install the new ignition coil and ensure it is properly seated.

4. Check Fuel Injectors

• If misfire persists, inspect the fuel injectors for proper operation.
• Remove the fuel rail if necessary, and use a fuel pressure gauge to check system pressure.
• Clean or replace any faulty injectors as needed.

5. Vacuum Leak Inspection

• Inspect all vacuum hoses and intake manifold gaskets for leaks.
• Use a smoke machine or carburetor cleaner to identify leaks.
• Replace any damaged hoses or gaskets.