Loss of power no error message
 

Please help! Not really sure where to start. I have a 06' 9-3 (auto)sportscombi - love it but...., it has lost probably about 40% of it's power. One day I heard kind of a grating noise from somewhere close to where I think the exhaust system might start underneath the car and the car lost about 30-40% power. The grating news continued for about 10 minutes then I hear what almost sounded like something breaking, or catching underneath and then no more noise, but still no more power. As a kicker too, no error code on the SID. Brought it to a Saab Mastertech (supposedly) and they could not find anything wrong - changed the plugs and charged me $180. There is still no power, supposedly no error code, and I have no idea what to do next. It seams to really struggle at about 1950 RPMS, and it looks like the Turbo is working overtime (and I can still hear it so I hope its not that). I thought maybe I should just take it to another mastertech but did not know if someone else had an idea first. Thanks for any help. It's my first saab, I love it, but getting tired of being burned by Corolla's

possibly the turbo...this happened to me i was losing power and i actually had to end up replacing the hose i was losing boost pressure...came to about 400 dollars...wont know for sure unless you take it to a saab station not to state the obvious