why does my Toyota Highlander Third Generation (2014-2019) engine misfire when accelerating

Solution

1. Preparation

• Gather necessary tools and parts.
• Disconnect the battery to prevent electrical shorts.
• Ensure the engine is cool before starting work.

2. Replace Spark Plugs

• Remove the engine cover if applicable.
• Use a socket wrench to remove the spark plug wire/coil from the spark plug.
• Use a spark plug socket to carefully remove the old spark plugs.
• Inspect the spark plug gap and condition; replace with new plugs as necessary (typically OEM or equivalent).
• Torque the new spark plugs to the manufacturer’s specifications (usually around 13-15 ft-lbs).

3. Inspect and Replace Ignition Coils

• Remove the ignition coil for the affected cylinder(s) as indicated by the diagnostic codes.
• If the coil shows signs of wear or damage, replace it with a new one.
• Reinstall the ignition coil and ensure it is securely connected to the spark plug.

4. Check Fuel System

• Use a fuel pressure gauge to test the fuel pressure at the rail. It should match manufacturer specifications (typically around 50-60 psi).
• If pressure is low, inspect the fuel filter for clogs or replace the fuel pump if necessary.
• Clean or replace any clogged fuel injectors.

5. Inspect Air Intake and Vacuum System

• Check the air filter for cleanliness and replace if dirty.
• Inspect the intake manifold for leaks using a smoke test or visual inspection.
• Replace any damaged vacuum hoses and ensure all connections are secure.