Originally Posted by JerryS
Correct me if I'm wrong but aren't tune ups mainly: changing sparkplugs, rotor, distributor cap, checking all fluids and changing what's neccessary, a test drive to see if any problems are present and check wheel and brake wear? I use to have the dealer do their tune-ups and that's mainly what they tell me they do; costs about $150; any thing else is extra. Most of this stuff you can do on your own. I did the last tune up myself and only cost me $50 in parts.
On modern cars it's a little different. For starters, cars don't have distributors, they all have electronic ignition & timing.
Otherwise, in most cases they will replace the plugs, check the timing, look for errors in the ECU. Clean the throttle body, add some premium fuel injector cleaner to the gas, check for vacuum leaks, and otherwise do a complete inspection of all other systems on that car.
On newer cars, this only need to be done every 100,000 miles (sooner if you drive lots of short trips or stop & go). On cars before about 2000, it's typcially every 60,000 miles.
On a 1999, it's probably about time if it's never been done before if you planning on keeeping the car for more tha 1 year or 20,000 miles miles. Otherwise, don't bother and trade the car in in a year on a new one.