I have a 2003 Cadillac CTS and I am having problems with the idle control. In the morning I am experiencing rough idle and on the first attempt to turn the car on it cuts off. After the second attempt though it cranks but the idle is high for a few seconds then it returns to normal. I have noticed that the car is also runninng a little rough. i took the car to a mechanic and he scanned it but he couldn't find anything. He asked me to bring it back in for a smoke test? Can you please help me with this issue so that I can have a better understanding of whats going on.