the list is not endless and there is light at the end of the tunnel.
check the following.
engine pads both front and rear blockl them off.
pipe to turbo from air box can close when under load if its soft it will proberbly need a new one.
intercooler is it split at the bottom.
what is your driving style like it could be the the vnt is sticking on the turbo to check this use a mittivac..
do a search on that code and you will find some interesting reading and fixes .
hope that helps.
http://www.volvoforums.org.uk/showth...hlight=ecm6805
mike