This machine initially had some fusing problem (tracking). I replaced the whole fusing assy with a new one DUNTW8600DS14 . A few days later very load knocking noise having to do with the Fusing pressure release. After a few days of this intermittent problem I did get a L4-16 code. I was told there was a bulletin about this problem, but don't know for sure. Not sure if I have to change something in the fusing pressure release assembly also because if a parts change mismatch. Or if problem is unrelated to the new fusing assy. Any help is much appreciated!