With the implementation of strict emission standards globally, the CGPF (Catalyzed Gasoline Particulate Filter) has become a standard emission control component for modern gasoline direct injection (GDI) engines. In urban traffic, frequent low-speed and stop-and-go cycles often prevent exhaust temperatures from reaching the threshold required for soot combustion, impacting compliance and increasing backpressure.

1. Technical Principles and Core Functions of CGPF

The CGPF (Catalyzed Gasoline Particulate Filter) is a composite component created by applying a Three-Way Catalyst (TWC) coating onto a wall-flow honeycomb ceramic substrate.

• Dual Purification Mechanism: It captures fine particulate matter (PM) while simultaneously utilizing the catalytic coating to treat CO, HC, and NOx.

   

• Regeneration Mechanism: The catalyst lowers the soot light-off temperature, enabling "passive regeneration" at lower exhaust temperatures and reducing reliance on forced regeneration cycles.

   

2. Performance Challenges Under Stop-and-Go Conditions

Urban driving environments present severe challenges for Mobile Source Exhaust Treatment.

• Carbon Accumulation Risk: Frequent idling and short trips lead to insufficient exhaust temperatures, causing soot to build up in the filter and potentially resulting in excessive backpressure.

   

• Thermal Stability Requirements: The catalyst must possess excellent thermal stability to withstand high-temperature regeneration events during occasional high-speed driving without deactivation.

   

3. Selection Guide and Maintenance Recommendations

When selecting replacement parts or optimizing systems in the Automotive Aftermarket, consider the following:

• Material and Coating Consistency: High-quality CGPFs must ensure even distribution of catalytic components to maintain stable conversion efficiency across all conditions.

   

• GHSV Matching: Selection must strictly match the substrate dimensions to the engine displacement to keep backpressure within safe limits.

   

• Periodic Monitoring: For vehicles operating primarily in congested areas, it is recommended to monitor the differential pressure of the DPF/CGPF using professional diagnostic equipment