defueling

[cpope]

I've searched, read and can't find anything on this:

my 01 Excursion w/211k lit the ses light the other day on the way home from dallas. code was low boost pressure. shortly after that it started defueling the motor around 2500 rpms. map line is clear, intercooler boots are tight. The clamp coming from the y-pipe to the turbo was loose so I tightened it up but the ses light is still on and it still stalls @ 3000rpms. Any ideas as to what's going on? It is a California model excursion. I don't know if that matters.

I'm baffled...