So, mine are installed along with a new cat-back exhaust (2.5" piping) and a Flowmaster 40, it sounds damn good and the power increase is amazing. But my problem is this. My car idled at about 600 rpms before all of this work. I was leaving the shop yesterday and about half way home the Service Engine Soon light clicks on and my rpms drop to about 400-300 at idle, but this is only when in gear. In neutral it still rests about 600. So at the moment I have no clue as to what the problem may be. Any and all input would be greatly appreciated.

You need to pull the code. It could be a lot of things but what comes to mind, that would be related, would be an O2 sensor not hooked up properly.

Is there an idle adjustment screw on this motor?

And maybe there is a vacuum leak..

Yeah, I need to hunt down a friend with a code reader. But my guess was also an 02 sensor because for the install I had to get 2 brand new ones, 50 inch long ones instead of the 30's.

any sound clips yet?