Puttering SR20 and rough cold start

[xStix99x]

Ok, I have a redtop sr20det that recently started running a little rough. When I start the car cold it sputters a lot and shakes and then finally mellows out, but then when it's idling it sits at 850RPM and bounces up and down to 950RPM constantly. You can hear it in the exhaust and feel it in the car if you are paying attention. I put on a stock clutch fan and the problem seemed to get worse, but I wouldn't think it was because of the fan. So I took a look at my MAF and when I touched the pigtail the engine would die, so I thought it was a bad MAF or pigtail. I got both a new pigtail and MAF, but it didn't fix anything. I cleaned the throttle body with a toothbrush and some cleaner, and I changed all my spark plugs with NGK Iridiums. I replaced two vacuum hoses that seemed brittle, but no I haven't done a proper vacuum test or a smoke test. Isn't a vacuum test the same thing as having a boost gauge anyways, because at idle my car has about 18Hgs and boosts up to the normal 8psi. I know I need to do a smoke test, but is there anything else that it might be? Anyone have a similar issue? I've found a lot of forums where people have the same problem, but the forum just stops without a solution. Also, I have a high flow cat that is a little over a year old, but it didn't pass emissions this year. Could the cat be causing this problem? I got this cat LG Motorsports (http://www.lgmotorsports.com/product_info.php?products_id=2159)

Any suggestions? Thanks in advance, and sorry for the long post.