First time I've had this happen, thought it noteworthy.
I replaced all the vacuum lines in the 945 three years ago, cloth braided from FCPG.
Brick was slightly sluggish the past couple days, last night on the way home from the Hill I started getting backfires.
How can this be thinks I?
Manifold to CBV line was toast, literally. Broke into pieces as I was removing it.
Confirmed by an independent adjudicator:
Dunno if it was bad hose, or what... Greatest fail was where it passed over the valve cover and near the exhaust manifold.
I know it gets warm there but sheesh, three years.
Proving once again that stage zeero is never permanent, and failures can occur even where you knew you were good.
Time for silicone lines I guess.