Hello,
P0401 relates to insufficient flow from EGR valve. This can be caused by a faulty EGR valve or a blocked EGR passage from the valve to the inlet manifold.
How to access and clean the EGR passages in the inlet manifold.
https://youtu.be/Xh9ieHEfUB4
See picture below how the EGR valve looks like.
Please let us know how you get along.
Cheers, Boris
Image (Click to make bigger)
Tuesday, October 12th, 2021 AT 9:04 AM