my Toyota Highlander Third Generation (2014-2019) engine hesitates during acceleration what should I...

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal for safety.

2. Replace Spark Plugs

• Sub-steps:
  1. Remove the ignition coils from the spark plug wells by unbolting them and gently pulling them out.
  2. Use a spark plug socket and ratchet to remove the old spark plugs.
  3. Inspect the gap on the new spark plugs and adjust to manufacturer specifications (typically 0.043 inches for most Toyota applications).
  4. Install the new spark plugs by hand to avoid cross-threading, then torque to manufacturer specifications (usually around 13 lb-ft).
  5. Reinstall the ignition coils and secure them with bolts.

3. Clean or Replace the Throttle Body

• Sub-steps:
  1. Remove the air intake duct from the throttle body by loosening the clamps and disconnecting any sensors.
  2. Use throttle body cleaner and a soft brush to clean the inside of the throttle body, ensuring that the butterfly valve operates smoothly.
  3. If replacement is necessary, unbolt the throttle body from the intake manifold and install the new unit, ensuring new gaskets are used.
  4. Reconnect the air intake duct and any sensors.

4. Fuel System Inspection

• Sub-steps:
  1. Connect a fuel pressure gauge to the fuel rail and turn the ignition to the "ON" position without starting the engine.
  2. Note the fuel pressure; it should typically be between 50-60 psi for this model.
  3. If pressure is low, check the fuel pump operation and replace if necessary.
  4. Clean or replace the fuel injectors using an appropriate fuel injector cleaner or by having them serviced.