Can somebody can confirm that EGR only kick in only in ASM 1550 testing. EGR does not work during ASM 2525 testing.. If a vehicle fail on NOX on both 15mph and 25mph than its not egr???????
Are you asking if this is true for all platforms? If so, no.
If you are asking about a specific vehicle, I doubt anyone can tell you that information either, unless that tech works on a specific manufacturer and has documented the data.
If you have a failure, perhaps you can tell us what year, make, model and engine size. Post all of the gases measured. I'm not saying that I can diagnose what is wrong with your vehicle, but perhaps I or someone here can direct you towards a solution. What data have you collected? What testing have you done?
Why make it simple, when it will work equally as well complicated.