i've figured out now that my car is running rich and my friend said to get a tune up where they adjust such parts as the the throttle body. what other things should be adjusted to get me back to optimal performance.

 

A/F ratio is controlled by the PCM. If everything is working correctly, it will maintain the required 14.7:1 stoichiometric A/F ratio in closed loop. A stock LT1 PCM tune will run on the rich side at WOT, typically around 11.7:1(varies, based on power enrichment calculations).

How did you determine your engine is running rich? Under what conditions does it run rich - idle, part throttle, WOT, all the time?

Typical causes of rich conditions are things like misfires, leaks in the exhaust system before the O2 sensors, leaking EGR valves, faulty O2 sensors. Rich conditions can also be caused by things like excessive fuel pressure, but the PCM should be able to compensate for this using the long term fuel trims.

To identify the cause of your problem, you really need a good scan for normal driving and for a couple of WOT passes, with enough data to plot the long term fuel corrections for most of the 18 data storage cells.