Mercedes CLC-Class Diesel Particulate Filter DPF Cl203 (2000-2011)

The DPF is an exhaust system component designed to capture and filter out diesel particulates (soot) from the engine exhaust gases. On the Mercedes CLC-Class CL203 diesel models, especially those with the OM646 engine, the DPF traps 95-99% of harmful emissions to comply with Euro 4 and newer pollution standards. It is integrated downstream of the turbocharger and includes sensors to monitor particulate accumulation.

The diesel engines equipped with a DPF in the CLC-Class CL203 are primarily the 2.1 L 4-cylinder OM646 engines found in the CLC 200 CDI (122 hp) and CLC 220 CDI (150 hp) models. These engines use common rail direct injection and turbocharging, paired with an exhaust system containing the DPF to reduce particulate emissions.

The DPF captures particulate matter by filtering exhaust gases as they pass through a ceramic monolith structure. It periodically regenerates by burning accumulated soot:

• Active regeneration: the engine management initiates post-injections raising exhaust temperatures above 600°C to burn off soot.
• Passive regeneration: continuous driving at adequate speeds and temperatures supports soot combustion naturally.

Pressure sensors monitor the filter's clogging level and trigger regeneration cycles as needed.

Symptoms indicating DPF issues include:

• Reduced engine power and acceleration loss
• Persistent illuminated DPF warning light on the dashboard
• The vehicle going into limp mode (reduced performance mode)
• Increased fuel consumption due to impaired exhaust flow

If these symptoms appear, it is recommended to have the vehicle diagnosed with an OBD scanner for DPF-related error codes such as P2002 or P2459.

DPF maintenance includes regular regenerations approximately every 300 to 500 km depending on driving style. Replacement intervals depend on usage:

• Typically every 100,000 to 200,000 km.
• City driving with short trips may cause faster clogging and reduced DPF life.
• Use of low-SAPS 5W-30 engine oil is recommended to reduce ash build-up.

If the DPF cannot regenerate successfully and is heavily clogged, professional replacement is required.

Replacing the DPF involves the following procedure:

• Safely lift the vehicle and access the exhaust system underneath the chassis.
• Remove the lambda sensors and pressure sensors connected to the DPF.
• Loosen and remove clamps and bolts securing the DPF (torque bolts carefully at 25-30 Nm).
• Clean the mounting area and fit a new OEM or equivalent quality DPF unit.
• Reinstall sensors and clamps, then reset the DPF system with official diagnostic tools (e.g., Star Diagnosis for Mercedes).

Vehicle inspection and DPF sensor calibration after installation is recommended for optimal performance.

The original DPF reference is Mercedes part number A2034900082. Equivalent high-quality DPFs from reputable manufacturers are also suitable if confirmed compatible by VIN or reference check. When choosing replacements, consider these factors:

• Compliance with manufacturer specifications and Euro emission standards
• Stainless steel construction with high-grade ceramic monolith
• Certification for performance and durability
• Warranty and after-sales support

Always verify compatibility before purchase to ensure proper fit and function.

DPF removal or bypass is generally not recommended for the Mercedes CLC-Class CL203, as it will cause increased emissions and likely violate environmental regulations in many countries.

• Removing the DPF may trigger error codes and limit vehicle performance via limp mode.
• Legally, tampering with or removing an emission control device like the DPF may lead to fines and failed vehicle inspections.
• Manufacturers design the DPF system to ensure compliance with pollution standards and protect the environment.

Proper maintenance and replacement of the DPF is the safest and most responsible approach.