I have a rough/ hunting idle. It all started right after I installed all the mods in my sig. I did them all at one time. At first the surging idle was do to not running a pcv valve and running a breather. I ran one night like that and dug into it because I was pushing so much oil out the breather under boost. So now I am running a welded shut pcv valve and a 3/8 hose out the top of my oil fill cap to vent the crank case. Even after I fixed the huge vac leak it still was surging. I know it isn't a vac leak because I searched with carb cleaner 3-4 times and my trims are as low as -10 at an idle. I have not and am not throwing any codes. I have replaced the maf, IAC, and O2 sensors. The thing is it doesn't always hunt. It is kind of random sometimes being worse than others. Sometimes it will hunt up to a 1000rpm difference and sometimes it is only a 400 rpm difference. It seems to get worse when it warms up. BTW I am running stock injectors because I wanted to eliminate the 65#'s. The car seems to run very good anywhere above 1000 rpm. If I think of anything else I will update this thread.