Periodic maintenance is different than tunning. If your car is runing perfect, no need of tuning, but you must do its maintenance like periodic oil and filter change, cleaning of some parts, checking some parts, etc etc Whereas tuning is to tune up your vehicle if its giving you poor mileage or performance.
So in ur case, the car is ok, just go with normal msintenance and take note of everything you changed. Observe any abnormal events.