Hi
I was fighting with low power boost error , and limp mode. Went to several workshops. Change vacuum lines , vacuum valves, egr, recirculation valve. Spend ton of money and still car went to limp mode very often.
So I bought obd scanner with display , and I checked live data when driving. Map sensor data was quite high 80-90 , and just changing between this values. I made a shot and changed map sensor. No errors car driving perfectly. I just want to mention that there was no error code for MAP sensor. It was giving wrong values. So I spend around 800 usd in workshops, and I was close to replacing turbo. I know it is old car , but maybe someone find it helpful.
I am sorry form my English but it is not my native language.