I know this topic is old news now, but just incase anyone else came across this problem at idle ive found the solution, well for me anyway.... all i needed to do was loosen the little screw on the AAC valve, you will find it at the back of the intake manifold close to the driver side window, there will be a plug connected with a purple plugtop for those who dont know already, it just looks like a normal screw, to increase airflow on idle just turn it counter clockwise while the engine is still running, you should notice a change with one revolution or two.... well fixed my problem anyway good luck