What's the top-spec version of Citroën C4?

The automobile exhaust system is mainly composed of an exhaust manifold, a catalytic converter, a midpipe, and a tailpipe (including a muffler). The exhaust manifold is directly connected to the engine cylinder head, collecting exhaust gases from each cylinder through branch pipes and channeling them into the exhaust main pipe. Its key components include a three-way catalytic converter and an oxygen sensor: the former converts harmful gases into harmless substances, while the latter monitors oxygen content in real time to optimize the air-fuel ratio. The midpipe is made of SUS304 stainless steel and typically features a double-layer corrugated pipe with a steel wire mesh structure, combining flexibility and durability to effectively mitigate vibration-induced damage during operation. The tailpipe is positioned near the rear bumper; the integrated muffler reduces noise through multi-channel airflow diversion, with some models additionally equipped with expansion joints to enhance noise suppression. The entire system employs a modular design from the hot end (engine side) to the cold end (rear vehicle side). All components work in concert to achieve three primary functions: exhaust gas purification, backpressure reduction, and noise control, ensuring compliance with environmental standards while improving ride comfort. Notably, exhaust pipe configurations such as S-bend and G-bend designs influence acoustic characteristics, while material selection directly impacts corrosion resistance and thermal stability.

The automotive exhaust system is an indispensable core component of a vehicle, and its importance is mainly reflected in three aspects. First, it collects exhaust gases from each cylinder of the engine through the exhaust manifold, transports them to the three-way catalytic converter via the exhaust pipe, and converts harmful substances such as carbon monoxide into harmless gases like carbon dioxide, ensuring compliance with environmental regulations. Second, the muffler in the system reduces exhaust noise to approximately 20-30 decibels through the principle of sound wave cancellation, significantly improving driving and riding comfort. Finally, as an end device, the exhaust tailpipe needs to ensure that exhaust gases are safely discharged outside the vehicle, preventing high-temperature gas backflow from damaging the engine. It is worth noting that the design of the exhaust system also affects engine performance; for example, equal-length exhaust manifolds can optimize airflow efficiency, while the working efficiency of the catalytic converter is directly related to fuel quality, so it is recommended to use fuel that meets the RON95 or higher standard. If exhaust abnormal noise or power reduction occurs, it may be due to muffler perforation or catalytic converter blockage, and timely maintenance should be carried out to avoid more serious mechanical damage.

The exhaust system is an indispensable component of an automobile. Its main functions are to efficiently discharge exhaust gases generated by engine combustion, while achieving environmental protection and comfort goals through multiple technical means. The system consists of components such as the exhaust manifold, exhaust pipe, catalytic converter, muffler, and tailpipe that work in coordination. The exhaust manifold is responsible for collecting exhaust gases from each cylinder; the exhaust pipe transports the exhaust gases to the catalytic converter, which converts harmful carbon monoxide, hydrocarbons, and nitrogen oxides into harmless carbon dioxide, water, and nitrogen through three-way catalytic technology, significantly reducing exhaust pollution. The muffler reduces exhaust noise using the principle of acoustic wave interference and sound-absorbing materials. Common resistive, reactive, and composite mufflers can suppress noise at different frequencies, improving driving quietness. The design of the tailpipe needs to consider the engine layout; V-type or large-displacement engines often adopt dual-exit exhaust to optimize air flow. In addition, the exhaust system improves intake efficiency by reducing back pressure, indirectly enhancing power output and fuel economy. Regular maintenance includes checking the sealing of pipelines, the condition of the catalytic converter, and the integrity of suspension components to ensure the long-term stable operation of the system. Modern exhaust systems also integrate oxygen sensors and EGR (Exhaust Gas Recirculation) technology: the former adjusts the air-fuel ratio in real time, while the latter reduces combustion temperature through exhaust gas recirculation, further reducing nitrogen oxide emissions and complying with strict environmental regulations.

The main function of an automobile exhaust system is to efficiently treat and discharge the exhaust gases generated by engine combustion, while reducing noise and minimizing environmental pollution. This system consists of components such as the exhaust manifold, exhaust pipe, catalytic converter, muffler, and tailpipe, which work in coordination. The exhaust manifold collects exhaust gases from each cylinder and reduces airflow interference; the exhaust pipe transports the exhaust gases to subsequent treatment devices; the catalytic converter (especially the three-way catalytic converter) converts harmful substances like carbon monoxide and nitrogen oxides into carbon dioxide, water, and nitrogen through chemical reactions. The muffler reduces exhaust noise using the principle of sound wave cancellation or electronic technology, while the tailpipe ensures that the purified exhaust gases are safely discharged outside the vehicle. For V-type or large-displacement engines, a dual-tailpipe design can improve exhaust efficiency. Regular maintenance of the exhaust system (such as checking the tightness of pipelines, the condition of the catalytic converter, and the integrity of the muffler) is crucial for maintaining vehicle performance, extending component lifespan, and complying with environmental protection standards. In addition, modern exhaust systems are also integrated with components such as oxygen sensors and EGR valves to optimize combustion efficiency and further reduce emissions through real-time data.

The exhaust emissions from automobile engines mainly consist of harmless components such as nitrogen, water vapor, and carbon dioxide, but they also contain a variety of harmful substances, including carbon monoxide, hydrocarbons, nitrogen oxides, sulfur dioxide, lead-containing compounds, benzopyrene, and solid particulate matter. Carbon monoxide binds to hemoglobin, causing tissue hypoxia, which can be fatal in severe cases, while polycyclic aromatic hydrocarbons (PAHs) in hydrocarbons, such as benzopyrene, are strong carcinogens. Nitrogen oxides can irritate the respiratory system and may cause pulmonary edema, while sulfur dioxide, together with suspended particulate matter, increases the risk of respiratory diseases and forms acid rain in the atmosphere. In addition, even trace amounts of lead compounds in exhaust emissions can damage the nervous system, and solid particulate matter may carry heavy metals and pathogenic microorganisms; long-term inhalation can harm lung health. To reduce exhaust pollution, it is recommended to maintain vehicles regularly to ensure the efficient operation of engines and exhaust systems, use high-quality fuels such as unleaded gasoline or ethanol gasoline, and adopt smooth driving habits to reduce unnecessary emissions. Promoting electric vehicles and clean energy vehicles is also an effective way to fundamentally reduce exhaust pollution.