I have a 2009 g37x sedan, and I am having some issues with it. The first of which is a rough idle. It has about 95000 miles on it. It is idling between 1000 and 1100 rpm’s. I cleaned the throttle bodies and did all of the programming reset stuff and I am still having the issue. My other problem is the code p0603. I am really hoping that it is not the pcm because that would be pricy. What should I try before I finally cave and take it to an Infiniti specialist?