Porsche Cayman owners manual page 191

text version of content this owner's manual page from owners manual to the vehicle Porsche Cayman, year of production 2006:

How Emission Control Works Crankcase ventilation f Do not continue to operate your vehicle under these conditions, since raw fuel might reach When an automobile engine is running, it uses en- Through crankcase ventilation, undesirable emis-the catalytic converters. This could result in ergy generated through the combustion of a mix-sions from the engine crankcase are not permit-overheating of the converters. Federal law pro- ture of air and fuel. Depending on whether a car is ted to reach the outside atmosphere. These emis-hibits use of leaded fuel in this car. driven fast or slowly or whether the engine is cold sions are recirculated from the crankcase to the or hot, some of the fuel (hydrocarbons) may not air intake system. From here the emissions mix Fuel Evaporation Control be burned completely, but may be discharged into with the intake air and are later burned in the en- the engine crankcase or exhaust system. Addition-gine. al hydrocarbons may enter the atmosphere Fuel tank venting through evaporation of fuel from the fuel tank. Catalytic converters These hydrocarbons (HC), when released into the The evaporation chamber and the carbon canister air, contribute to undesirable pollution. The catalytic converters are efficient ”clean-up“ prevent fuel from escaping to the atmosphere at In addition, carbon monoxide (CO) and oxides of devices built into the exhaust system of the vehi-extreme high outside temperatures, when driving nitrogen (NOx) contribute to engine emissions. cle. The catalytic converters burn the undesirable abruptly around curves and when the car is parked They, too, are formed during the combustion proc-pollutants in the exhaust gas before it is released at an incline or in any other nonlevel position. ess and discharged into the exhaust system. into the atmosphere. To reduce these pollutants, your Porsche is The exclusive use of unleaded fuel is critical-Vapor control system and storage equipped with a precisely calibrated fuel injection ly important for the life of the catalytic con-When the fuel tank is filled, vapors are collected in system to assure a finely balanced air/fuel mixture verters. Therefore, only unleaded fuel must the evaporation chamber by a vent line leading the under all operating conditions. be used. vapors to the carbon canister where they are The catalytic converters will be damaged by: stored as long as the engine does not run. Oxygen sensor – push or tow starting the vehicle, The oxygen sensor, installed in the exhaust pipe Purge system continuously senses the oxygen content of the ex-– misfiring of the engine, f When the engine is running, the fuel vapors haust and signals the information to an electronic – turning off the ignition while the vehicle is mov-from the canister will be mixed with fresh air control unit. The control unit corrects the air/fuel ing or from the ambient air of the canister. This mix- ratio, so the engine always receives an accurately – driving until the fuel tank is completely empty, ture will be directed to the intake air housing by metered air/fuel mixture. – by other unusual operating conditions. the tank vent line, mixed with the intake air and burned during normal combustion. Maintenance, Car Care 191

owners manual Porsche Cayman

owners manual Porsche Cayman - year of production: 2006 - Porsche Cayman owners manual EN