Yes. The regeneration process leaves residual sulphated ash as a by-product of combusted engine oil. The main purpose for performing a basic pneumatic cleaning is to purge the residual ash from the cells of the DPF. In addition, the efficiency of a vehicles’ regeneration is dependent upon its duty cycle. Most vehicles operating conditions don’t promote perfect regeneration that would ensure that a DPF is completely purged of unburned PM (particulate matter) therefore must be cleaned periodically.
When and how often a DPF needs to be serviced depends on several variables. Engine RPM, duty cycle, idle time, fuel quality, engine oil quality and maintenance procedures can all have a tremendous influence on how frequently a DPF needs to be serviced. The most common methods for triggering a DPF service light are based upon the hours of operation, mileage or backpressure differential in the exhaust system. Always use the OEM service manual recommendations as guideline for your application. You may need more frequent cleanings based upon application and duty cycle.
