irish

I got a 1990 accord, I drilled and tapped the 4 EGR ports that were inline, should I also do the 2 infront. Sure enough the 4 were all clogged and I broke apart the carbon with a clothes hanger. Can anybody recommend anything else to do for this (failed NOx emissions, readings before were 1800, after 1200, but pass is a 1000) also, when the EGR valve lifts up under acceleration, should it stay open, or close back down when the throttle is steady? mine will surge open when given gas, then it seems to close after (still above idle) and not open again until it gets gassed. I have also heard that it is supposed to open and close periodically whenever above idle. whats the proper function if anyone can tell me. thanks.

dave