Mercedes CLS-Class Catalytic Converter

The catalytic converter of the Mercedes CLS-Class transforms harmful exhaust gases into less harmful substances like carbon dioxide and water through chemical reactions. It uses rare metals such as rhodium, platinum, and palladium to catalyze this conversion process. Exhaust gases pass through a honeycomb structure inside the converter where these metals facilitate the breakdown of toxic molecules.

The Mercedes CLS-Class can be equipped with different catalytic converter types based on the engine model:

• Three-way catalytic converter (gasoline engines): Treats carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx).
• Two-way catalytic converter (diesel engines): Treats CO and HC but not NOx.
• Close-coupled catalytic converter: Positioned near the exhaust manifold for higher temperatures and improved efficiency.

Some CLS-Class models, such as the CLS 350 CGI V6, have multiple catalytic converters along the exhaust line for optimized emissions control.

Several key components interact with the catalytic converter in the CLS-Class exhaust system:

• Oxygen sensors (Lambda sensors): There are typically two sensors placed before and after the catalytic converter. The upstream sensor monitors oxygen levels to optimize air-fuel mixture, while the downstream sensor verifies efficient converter operation.
• Diesel Particulate Filter (DPF): On diesel models, the catalytic converter is often integrated with a DPF to capture and burn fine carbon particles.
• Selective Catalytic Reduction (SCR) system: For Euro 6 diesel engines, an SCR catalyst uses AdBlue additive to reduce nitrogen oxides (NOx) emissions.

These components collectively ensure emission compliance and efficient exhaust purification.

The catalytic converter effectively reduces several harmful pollutants in exhaust gases:

• Carbon monoxide (CO)
• Unburned hydrocarbons (HC)
• Nitrogen oxides (NOx), depending on catalytic converter type

These substances are converted into carbon dioxide, water, and nitrogen, which are much less harmful to the environment.

Common causes of catalytic converter failure include:

• Hardening of sealing mastic upstream damaging the ceramic monolith
• Melting of the monolith caused by excess fuel in the exhaust line
• Soot clogging that blocks contact between gases and precious metals
• Frequent short trips preventing the converter from reaching its optimal operating temperature (~420°C)

Signs of malfunction often include illumination of the engine warning light. Regular engine maintenance, avoiding short trips, and timely replacement of oxygen sensors help maintain catalytic converter performance.

The catalytic converter is a valuable and costly emission control device. Replacement involves significant expense due to its rare metal content and technology.

At Krosfou, high-quality original catalytic converters come with a 3-year warranty limited to 100,000 km usage. Our converters meet or exceed manufacturer specifications and European emission compliance standards.

• Warranty requires professional installation in specialized garages.
• Installation of new oxygen sensors alongside the converter is recommended after 80,000 to 100,000 km.
• Improper use or negligence voids the warranty.

Replacement parts are made with durable INOX 409 stainless steel and high-performance monoliths for long-term reliability.

Yes, some aftermarket sports exhaust systems designed for the Mercedes CLS-Class, such as Supersprint systems for the CLS 350 CGI V6 model, maintain compatibility with the original catalytic converter. This ensures compliance with emission standards while allowing performance exhaust upgrades.

• Original catalytic converters remain fully functional within such systems.
• Compatibility should always be confirmed by referencing the specific vehicle model and engine type.

Consult professional installers or product catalogs to ensure correct fitment and compliance.

The catalytic converter typically weighs between 1 and 10 kg, making it a relatively lightweight but valuable exhaust system component. It consists of a stainless steel housing (INOX 409 grade) containing a ceramic monolith with a honeycomb structure coated with a thin layer of rare metals like rhodium, platinum, and palladium. This design maximizes surface area for efficient catalytic reactions and durability.

Krosfou manufactures catalytic converters with advanced coating technology to ensure high performance and longevity for Mercedes-Benz vehicles including the CLS-Class.