Here's the deal.. I replaced the intake gasket mainfold about 2 months ago, and today it started doing the same thing idleing high then low.. It sounds like the samething that it did the 1st time I got the car... It a JDM GSR swap in a EG.. Also what ECU should I be runing.. It came with P30 chipped.. I am not sure what program it is though.... If anyone can help that would be great..

 

I bet you are having a problem witht he IACV on the back side of the manifold. Its near the throttle body, and easy to remove. The hardest part is removing the two coolant hoses on the lower side of the valve. Do this, take off the IACV and clean the two holes. These holes are on the side that mounts to the intake. Clean them with carb cleaner, and let it dry. After, install it and check again. BTW, is you CEL on? If so, pull the code and see if its a IACV code.