Are you sure about that? I think possibly you’re thinking of EGR (exhaust gas recirculation) which most engine manufactures used to handle the initial 2004 standards (which did not include particulate matter standards) but which is not really used any more. The main things used today are DPF (diesel particulate filter) and DEF (diesel exhaust fluid).
I’m not a diesel mechanic or anything, I just know what I know from owning a school bus (from 2003, yay!) and researching the emissions issues.
SmoothIsFast@lemmy.world 1 year ago
Yes, when the diesel particulate filters clog up with soot, the ECU triggers post injection events so that extra diesel fuel will burn in the exhaust raising the temperature of the diesel particulate filter and burning the soot out. These events cause your miles per gallon to decrease significantly.