What codes are being thrown when it goes into limp mode? Is it a MAF/MAP/TB Position correlation issue?
Have you tried disabling the Airflow Diagnostics? (under Engine Diag, General tab, top left corner)
You could also try changing the P0101/P0101B MAF Perf Airflow Delta Limit % (under Engine Diag, Airflow tab, top left box) from 25% to 50%, and bumping the P0106 MAP % from 8% to 16% to see if that helps - no guarantee it will help at all.
I'm assuming you are running a stock-ish exhaust with narrow band O2 sensors...have you logged the Bank 1 and 2 LTFTs and STFTs to see what they are doing? You could also log the MAF voltages and set up a graph to see what the LTFT+STFT values are...that should tell you percentage-wise how much fuel the PCM is trying to trim to keep the AFR at stoich under part throttle conditions.
The only decent way I know to get the MAF tables in line is to log wideband O2 sensor data vs. MAF voltage and set up a % difference graph (commanded vs. actual) to see what's really going on. I also know that these cars are extremely sensitive to any type of airflow change, but my experience is pretty limited. I'm still running a relatively stock car (high flow cats are the only mod so far), so I probably won't be of much assistance.