2003 Subaru Forester Owner's Manual - Page 271

Driving tips Catalytic converter " 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. HS8002BA 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. To avoid damage to the catalytic converter: " Use only unleaded fuel. Even a small amount of leaded fuel 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. " Avoid fire hazards. Do not drive or park the vehicle anywhere near flammable materials (e.g. grass, paper, rags or leaves), because the catalytic converter operates at very high temperatures. " Keep everyone and flammable materials away from the exhaust pipe while the engine is running. The exhaust gas is very hot. 8-4