“Reconditioned”, baked or cleaned diesel particulate filters (DPF) units offer short term financial benefit. In terms of functionality, the overall cost to the customer is much higher. In reality these processes can deactivate the original catalyst and stress the DPF substrate to an even greater extent during normal active regen cycling.
Reconditioned units present an extensive history of soot accumulation and regeneration, which will expose both the substrate and washcoat to significant thermal extremes. This compromises the mechanical strength of the substrate and the catalytic performance of the washcoat.
High temperature regen or “baking” events result in the sintering of the dispersed catalyst in the washcoat. Additionally, the base metal components of the washcoat will undergo crystal growth and porosity collapse, resulting in decreased Nitrogen Deoxide make, which increases the frequency of active regen, adversely impacting fuel economy.
The repeated thermal cycling of the DPF subjects the substrate to repeated severely thermal expansion and contraction events, which potentially results in failure of the DPF.
Reconditioned or aqueous cleaning could potentially also deactivate the catalyst as the reverse flow injection of the cleaning solution can result in loss of the washcoat.
