One problem related to manifold/header/muffler/tail pipe has been reported for the 2007 Subaru Outback. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2007 Subaru Outback based on all problems reported for the 2007 Outback.
Oil leaking from passenger side head gasket onto exhaust manifold. Read web and see this is a very common failure item for Subaru engines 2000 thru 2009. My concern is potential fire. Repair costs $1800-3000. Widespread issue and fire hazard thus I hope Subaru will address this design issue more proactively.