1998 Subaru Impreza Owner's Manual - Page 167
1998 Subaru Impreza Manual
Page 167 highlights
Catalytic converter D 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. D Keep everyone and flammable materials away from the exhaust pipe while the engine is running. The exhaust gas is very hot. WARNING Catalytic converter OM-H0381 The catalytic converter is installed in the exhaust system. It serves as a catalyst to reduce HC, CO and NOx in exhaust gases, thus providing cleaner exhaust. To avoid damage to the catalytic converter: D Use only unleaded fuel. Even a small amount of leaded fuel will damage the catalytic converter. D Never start the engine by pushing or pulling the vehicle. D Avoid racing the engine. D Never turn off the ignition switch while the vehicle is moving. D 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. D Do not apply undercoating or rust prevention treatment to the heat shield of catalytic converter and the exhaust system 7-8