Video to help diagnose fault code p0401 EGR insufficient flow fault code on a vw Passat TDI with a 1.9 pd engine fitted. In this case a failed EGR valve.
It depends on the driver. The Diesel engines are espicially produced for longer routes per day. Like 50km per day. When you only drive your Diesel car in the city, you just dont give your car the opportunity to burn the soot. And this one of the reasons ^^
Before you change EGR Valve, test it with a vaccum pump (EGR membrane). My valve turned out to be functional so i didnt have to change it. The problem was a thin rubber hose that was kinked(bent) going to tu EGR Valve. Check all the hoses going in and out of the EGR. After all this delete code and try again.
