Newbie

Hello all,I am new to this forum.I have a 99 grand am 2.4l L9 that failed
emissions recently.The nox readings were 3 times the limit.All other spec are well within what they should be.This engine does not have an egr valve.Any information on what could cause this is much appreciated.
Thanks for your help.

overheating or hot running engine will cause that. Check thermostat and coolant level, bad cat.

Thanks for the info.This car is not over heating.Temperature guage reading normal.