Idler Arm Loose
Do you have a factory service manual? There's probably a spec for it. I know on S/10 trucks for example there's a spec for idler arm "slop". There should be no more than 1/4" from one extreme to the other. It's a different design, mind you, but the reason is the same. If the idler arm is too tight, that will affect steering return to center. I don't "know" if there's a spec similar to that in the book for our cars or not.....as I've not looked, but it's best to consult with the service manual first, rather than "wing it".