HC - 79 percent reduction
CO - 41 percent reduction
NOx - 52 percent reduction
O2 - 100 percent reduction to zero (It was all being used by the cat, which is what you want)

One thing that is not clear is if you adjusted your duty cycle before or after you replaced the possibly leaky EGR valve.

Obviously a vacuum leak is going send the duty cycle out of whack as the system tries to richen to compensate for the additional air, so before you check and adjust the duty cycle, ensure that there are no vacuum leaks.

You should be in good shape for the future as you now KNOW how to pass the test. You did a good job reading and understand all the referenced information on how to "tune for emissions", and this should be an example for all.

It shows how a little judicious "tuning" can turn a failure into a pass with lots of margin, notwithstanding the fact that you probably had a leaky EGR valve.

Duke