I meant a live scan (with a full scan tool) while driving. Goose it. There should be a parameter "boost %" or "boost duty cycle" or something like that. If it doesn't say 100% when you are hard on the gas, the PCM sees a problem and is dumping boost on purpose. I can look at my PSM later when I get home to see the diagnosis of code 56.
If it always says 100%, but you don't get 100% boost, you need to get a new BCS.