Smart 451 CDI 45HP Limp Mode EGR

[yinujim]

Hi I have a Smart 451 45HP and it goes into LIMP mode after a minute of running. I'm getting code P0401 Flow Insufficient Detected has been detected.

I've cleaned out the EGR and mixer tube but the problem still persists. The EGR is not siezed. Does anyone have a clue what the issue could be?

Thanks