Well when I did my first boost leak test I found a leak around the shaft seals, but that was very recent and consequently I do not yet have the new seals to install (on order). Could this be the cause of the terribly rich and fluctuating idle as well? I was just chatting with Brad and he suggested I check my plugs and I think I will try some MAF cleaner at l2r99gst's suggestion about a potential MAF problem.

 

I had a leak around the shaft seals but didn't have this problem but maybe yours is more significant.

 

Well the weather finally broke today and I got around to working on the car again. I did not have much time, so I made several changes at once, although I would have liked to do things in steps to narrow down the diagnosis. I checked my plugs (rich) and regapped them (they were ~ .040), I cleaned the MAF with some MAF cleaner, and I reflashed once again for good measure. Everything is back to normal. Fuel trims and AFRs are within the norm and it seems like the initial slight richness (before the AFRs in the 9.0s) may have been the boost leak that I addressed. I would like to attribute the weird symptoms to the flash, but I really do not know what caused the idle problems and super richness. Nevertheless, all is resolved and I want to thank everyone for their suggestions and assistance.

 

ehh, why would you blame the flash if it's the only thing that didn't change from when it went belly up to when it was resolved?