BM Catalysts urges winter preparation for diesel emissions systems

As temperatures fall, BM Catalysts is encouraging workshops to take a closer look at the entire emissions system when drivers report warning lights or reduced performance.

Winter driving can place additional demands on diesel emissions control systems, with cold starts, shorter journeys, and prolonged idling making it increasingly difficult for diesel particulate filters (DPFs) to reach temperatures required for effective regeneration. When this process is repeated and interrupted, soot can accumulate within the filter, subsequently restricting exhaust flow and potentially leading to warning lights, reduced performance, increased fuel consumption, and, in severe cases, limp mode.

A DPF is designed to capture soot produced during diesel combustion before periodically burning it away through regeneration. During sustained higher-speed driving, passive regeneration can occur naturally as exhaust temperatures rise. However, vehicles predominantly used for urban and stop-start driving may struggle to achieve the conditions required, meaning the engine’s management system may initiate active regeneration to increase exhaust temperatures.

Importantly, a blocked DPF is not always the root cause of the problem. Faulty injectors, EGR issues, damaged pressure pipes, and failed differential pressure or exhaust temperature sensors can all contribute to excessive soot loading or prevent the vehicle from correctly monitoring and completing regeneration. Simply diagnosing the DPF as the fault without identifying the underlying issues can therefore leave the vehicle susceptible to the same problem returning.

Technical Director at BM Catalysts, James Saunders, said, “Winter driving conditions can expose problems that have been developing across the emissions system; a DPF warning light should prompt a proper diagnosis rather than an automatic repair.”

Technicians and garages should consider the vehicle’s service history, typical journey pattern, and regeneration history, alongside differential pressure readings and exhaust temperature sensor data. Checking associated components such as pressure pipes, sensors, and mounting components can also help prevent repeat failures,” he added.

BM Catalysts recommends the winter period be used as an opportunity for wider inspections of emissions systems to take place, particularly on vehicles making frequent short journeys. Drivers should also be advised to follow the vehicle manufacturer’s guidance on regeneration procedures and oil specification, with the correct maintenance regime helping support long-term DPF performance.

Where replacement is necessary, choosing the correct component and ensuring it is a proper fit are equally important. BM Catalysts offers a comprehensive range of type-approved DPFs alongside catalytic converters, SCR units, and pressure pipes. To supplement the vast offering, BM Catalysts also provides technical resources covering DPF fitting advice, common fault codes, exhaust leaks, and pressure testing.

With the right diagnosis this winter, technicians and garages can help their customers avoid repeat repairs and keep vehicles operating efficiently. Taking a preventative approach now can help address developing issues within the emissions systems before they become more costly problems.

For more information on BM Catalysts’ emissions control range and technical resources, click here.