I have been having a very low idle issue ever since I bought the car about 2 months ago. I have tried a ecu reset without any change. When I start the car cold, the car idles normally. Once the car is at normal operating temperature, the idle drops all the way to between 250-350 rpm's. With the ac on, the rpm's rise up to around 600 rpms. The car never dies from low idle but it does start to shake without the ac on at a stop. I havent had a chance to get it looked at. What do you think the issue could be? Throttle body or a Vacuum leak possibly?