What is included in a tune-up? on 2004 Chevrolet Trailblazer

What services are included in a tune-up?

A Tune-up on a late model vehicle commonly consists of replacing the spark plugs, air and fuel filters. These items would normally be replaced during one of the routine service intervals with the air filer being replaced most often. If the vehicles scheduled maintenance is followed, performing a "tune-up" would not be necessary.