i have a 98 eclipse rs when putting it to P, R, or D i'd get a clicking sound dont know what it is..also when slowing down to a red ligth or whatever car will jerk or slip then hit kinda hard for some reason.. what do u guys think it is ..pleae help

i only put cat back exhuast system with air intake system ..tryin to build it up but trying to find out what this problem is first.

First things first, have you checked your fluid level? The way your going to want to do that is with the car warm and running, and the trans in drive, put the e-brake on so you don't have to run next to the car. You're checking for both fluid level and to see if it's burned. Ten to one it's fluid. After that you're going to have to get more specific with symptoms.