Today's automobiles do not require "tune-ups". The term indicates the need for routine maintenance and should not be associated with poor performance. Automobile manufacturers have developed recommended routine maintenance schedules, which specify intervals for replacing spark plugs, PCV valves, fuel filters, etc. These schedules also specify intervals for checking and adjusting ignition timing, idle speed and other items related to engine operation, as well as emission-control related devices.
If your vehicle experiences any operating or performance problems between maintenance intervals, that specific problem should be addressed by performing an engine analysis to isolate the particular problem.