hypeR speed

Hey all I've got a 98 Turbo'd GSR w/ Greddy bolt on kit. I'm having a bit of a problem with the turbo. Starting a couple weeks ago I started getting CEL 71 72 73, random misfires in cylinders 1 2 and 3. If i give anywhere near full throttle, starting around 4k rpms i'd feel a loss of power I'm not sure if its related to the misfire, or if im pinging. It's worse when the engines is fully warmed up. Then today I was on the freeway in some traffic, not really pushing it but all of a sudden I noticed my engine was idling at 1.1k and i was running very rich.. Black smoke was coming out of my exhaust. This time CEL 3 was on, MAP - manifold absolute pressure sensor. Anyways, I let it cool down, and then reset the ecu while i went to get a drink, and now it's fine, no cel yet, but I'm pretty sure if i run it hard i'll get the cel again. I'm confused as to what is causing it. The greddy kit should be a direct bolton, it also comes with the fuel management not the emanage. I have 1 step colder plugs, gapped at .32. I'm going to try to gap it at maybe .28 or .30 and hope for the best. Are there any downsides to gapping it to small?