Hello,
First, he should only try it for testing purposes, and second, an error message only appears if you disconnect the connector from the EGR solenoid valve.
It's best to disconnect the hose from the EGR valve and seal it, for example, with a screw, and also close the connection on the EGR valve itself, as otherwise dirt may get in.
And if that's it, then there's a guaranteed new AGR.
Thank you, Thomas. If that was all, then it's perfect; it really helped me a lot.
I'll head straight to the workshop on Monday.
See you next time!!!