Why does my 2020 Toyota Highlander have a rough idle?

Rough Idle Diagnosis for 2020 Toyota Highlander

Tools Required

• OBD-II scanner
• Fuel pressure gauge
• Spark plug socket and ratchet
• Multimeter (for electrical checks)
• Throttle body and MAF cleaner
• Smoke machine (optional for vacuum leaks)
• Compressed air (for cleaning components)

Repair Instructions

1. If Codes Indicate Misfires:

   • Replace faulty spark plugs and ignition coils as required.
   • Clear DTCs and test drive to see if the issue persists.

2. If Fuel Issues are Identified:

   • Replace a failing fuel pump or clean/replacement of clogged fuel injectors.
   • Ensure proper fuel pressure is maintained.

3. If MAF Sensor is Faulty:

   • Clean the MAF sensor or replace it if damaged.

4. If Throttle Body is Dirty:

   • Remove the throttle body and clean it using throttle body cleaner.
   • Reinstall and reset the throttle position sensor (TPS) if necessary.

5. If Vacuum Leaks are Detected:

   • Replace any damaged vacuum hoses or gaskets found during inspection.
   • Perform a smoke test to ensure all leaks are sealed.

6. Final Steps:

   • After repairs, clear all DTCs using the OBD-II scanner.
   • Take the vehicle for a test drive to ensure the idle has stabilized and all symptoms have been resolved.

Conclusion

If, after following these steps, the rough idle persists, it may be necessary to consult with a professional technician for further diagnostics, as underlying issues could involve deeper engine problems or advanced sensor malfunctions.