Turbo Bypass Valve Issues

[TM]

If it's a "fluttering" sound, yes, it sounds like you have bypass valve
failure. Need to fix that right away, IMHO. Does your car inexplicably
stall when coasting to a stop?

This definitely can contribute to a low boost problem- check
www.sjmautotechnik.com
for detailed troubleshooting in the "ABCs of High Boost, 20v" section.

I wouldn't even bother w/ the MTM (which is a Bosch valve for a Saab 9-3
Viggen,
IIRC). Instead, I'd consider getting one of the aftermarket valves-
Bailey (can
be had from www.awe-tuning.com) or Forge (from Stratmosphere-
www.stratmosphere.com).

If you want cool sounds, the Bailey valve makes a bit of a "phssssst"
sound when
the engine is relatively cool and the throttle is shut. :-)

Taka