do you guys mean the problem occurs when you are coming to a stop? like the car will "clunk" or "jerk" when it's about to stop? If so, I think the problem is worse when you turn off the AC because it will drop the idle lower. I'm having this problem on my 540 now. I'm still trying to find a fix. Some guys suggested to update the AGS software which the previous owner already did and still no luck.

more details on your problem will be helpful.