random idle fluctuation and engine stall

[Ariamius]

My 7m gte in 88 supra turbo has a strange habit of idle fluctuation at red lights and just idling. idle sometimes ranges from 500 to 1200 rpm and occasional will completely stall at idle. Check engine light is on also. I know I have a small hole in the turndown pipe behind the turbo. compression test shows 165 to 170 on all cylinders. no misfiring or hesitation really while driving. Hopefully someone can shed some light on how to solve my issues. Any help would be great.