2008 Subaru Outback Owner's Manual - Page 295

8-4 Driving tips 2.5-liter turbo models To avoid damage to the catalytic converter: . Use only unleaded gasoline. Even a small amount of leaded gasoline will damage the catalytic converter. . Never start the engine by pushing or pulling the vehicle. . Avoid racing the engine. . Never turn off the ignition switch while the vehicle is moving. . Keep your engine tuned-up. If you feel the engine running rough (misfiring, backfiring or incomplete combustion), have your vehicle checked and repaired by an authorized SUBARU dealer. . Do not apply undercoating or rust prevention treatment to the heat shield of catalytic converter and the exhaust system. Periodic inspections To keep your vehicle in the best condition at all times, always have the recommended maintenance services listed in the maintenance schedule in the "Warranty and Maintenance Booklet" performed at the specified time or mileage intervals. 3.0-liter models The catalytic converter is installed in the exhaust system. It serves as catalyst to reduce HC, CO and NOx in exhaust gases, thus providing cleaner exhaust.