dump valve?

[Nicholas Lawrence]

Car is a '90 200tqa.
In the Bentley under fault diagnosis for code 2224 it says dump valve
defective, see repair group 21.
Is the dump valve the waste gate? I did replace the small hose on the top
side of the wastegate.
Has anyone ever experienced a stuck open waste gate? And shouldn't  the
boost guage still be able to report near 1.0?


On a drive under boost, 1.8 on dash gauge I lost power.  No "whoosh" of a
blown hose as I have heard in the past, and the car still runs.
Couldn't find any leaks with a stethoscope and the engine will stall when
the oil cap is removed.
I understand that a hose may leak under pressure that is otherwise not
noticeable but I now can't get any where near 1.0 on the guage, maybe .6 or
.7,         and it won't rev to red line in neutral.

Any ideas?            Maybe I sucked a shop towel into the airbox?

TIA
Nick