Hmmm, based on the std Co/HC/Nox curves, it appears you were running too rich on the first test, and leaned it a bit on the 2nd test, but not enough to bring the CO and HC down to spec. NOX will peak up the nearer the mixture gets to perfect, and go down when either rich or lean. HC/CO go up when rich. CO goes down the leaner it gets, but HC goes back up if the mix is excessively lean.

I've forgotten most of this stuff, but I got this from a chart somewhere in the archives, that one of the guys published. You might do a search to see if you can find it.

Sounds like your Lambda control is now working better, but did you check the EGR valve? May not be that, though, because it really doesn't come in at idle, and your low-high speed numbers are behaving similar.
definitely check all the temp sensors.

DG