Is it a vacuum leak? idle issue/running rich

[ReaperBJJ]

I've had a bit of a problem with my KA-E as of late. When I start it up it idles at about 1k, and slowly makes it's way to about 1200-1400, and then suddenly the idle will drop to about 500-600. Awhile back my friend brought over his vacuum gauge and it says my vacuum is fine until, the big rpm drop, then it's horrible. I already tried spraying starter fluid around any vacuum line and had no luck, I'm thinking about trying propane next.

One thing I was wondering that might be causing it is that the previous owner did a hack job removal of the EGR. Basically he just took a hack saw and hacked the hardline that goes from the exhaust mani to the EGR and bent the section still connected to the exhaust mani so it wouldn't leak bad. I've already properly plugged that end and am hoping to take off the EGR and plug it on the other end in a few days and see if that helps.

Anybody have any ideas? By the way, the aftermarket things done are 4-2-1 exhaust manifold, test pipe, and 3" catback, all eBay I think, and an Injen CAI. Lastly the previous owner said he replaced all the valves and retainers, shaved the head, port and polish, and 3 angle. I haven't torn apart the motor that much to confirm it, but with the way this kid did some other things on the car I'm nervous about the quality he did stuff or if he did them at all.

[ReaperBJJ]

bump up for the night, anybody know?