I think it was just loosen nuts. After I replaced the egr the failure was gone. So I wanted a look to the new egr valve. After I set the ratchet on the nuts I feel they where very loosen. So I fasten they up and the failure is gone the last three days.
Funny thing. I sprayed the whole engine with leak detector and no rpm changing was there. I think the egr did work with pressure and not with vacuum?