Do not alter or remove any component of the emission control system.
Do not alter or remove any device, such as heat shields, switches, ignition wires, valves, etc., which are designed to protect your vehicle's emission control system.
In addition to serious engine damage, this can result in a fire if excess raw fuel reaches the exhaust system.
Do not continue to operate your vehicle if you detect engine misfire or other unusual operating conditions.
Fire Risk When Parking
The exhaust system becomes very hot when the engine is running and remains hot for some time after the vehicle is turned off. Flammable material close to the exhaust system could ignite.
Do not park or operate your vehicle in areas where the hot exhaust system may come in contact with dry grass, brush, fuel spill or other flammable materials.
If your car catches on fire for any reason, call the fire department. Do not endanger your life by attempting to put out the fire.
Additional undersealing or rust protection agents on or near the exhaust system can become too hot when driving and ignite.
Do not apply additional undercoating or rustproofing on or near the exhaust manifold, exhaust pipes, catalytic converters or heat shields. During driving the substance used for undercoating could overheat and ignite.
How Emission Control Works
When an automobile engine is running, it uses energy generated through the combustion of a mixture of air and fuel. Depending on whether a car is driven fast or slowly or whether the engine is cold or hot, some of the fuel (hydrocarbons) may not be burned completely, but may be discharged into the engine crankcase or exhaust system. Additonal hydrocarbons may enter the atmosphere through evaporation of fuel from the fuel tank. These hydrocarbons (HC), when released into the air, contribute to undesirable pollution.
In addition, carbon monoxide (CO) and oxides of nitrogen (NOx) contribute to engine emissions. They, too, are formed during the combustion process and discharged into the exhaust system.
To reduce these pollutants, your Porsche is equipped with a precisely calibrated fuel injection system to assure a finely balanced air/fuel mixture under all operating conditions.
The oxygen sensor, installed in the exhaust pipe continuously senses the oxygen content of the exhaust and signals the information to an electronic control unit. The control unit corrects the air/fuel ratio, so the engine always receives an accurately metered air/fuel mixture.