RepairPal Certified shops can diagnose and repair your 1999 Porsche 911. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
Check here http://repairpal.com/automobile-owners-manuals-online or try this link you may be able to down load a free copy of the owner's manual for your vehicle http://www.autousermanual.com/
Perhaps post your question on a Porsche forum or call/drop bye your nearest dealer or independent Porsche repair shop.
