Our DPF delete pipe is made as a replacement part for a failed DPF. The pipe is the same material and OD as the original stainless steel exhaust system. The DPF delete pipe accepts all the original DPF sensors so the computer thinks there is a DPF fitted. With a DPF fitted the soot builds up in the filter. There are pressure sensors before and after the DPF. When the computer reads a difference in pressure a burn cycle is initiated. With the DPF delete pipe fitted  there is no pressure difference so there is no burn cycle.  With no burn cycle fuel savings of 1 liter per 100 kms is not unusual. There will be some black smoke seen when driving. The smoke will be the same amount as a manual transmission vehicle as they have no DPF. This product alters emissions and is for off road usage.