When you put the car in drive you should see the small rod coming out of the CSS extend to move the linkage by a couple of millimeters so as to increase the idle. You may need another person to do this test, as you can't see the CSS engage when you're inside the car, putting it into gear, plus you want to apply the brake when you do. Good luck, ithere's a host of possible causes here, work through them one by one.