nox too high-failed smog-assistance?

How do i significantly reduce the nox? i've tried fuel solvents, changed oil, adjusted the valves and changed o2 sensor..... any help would be appreciated
Oh yea, by the way, it's a d16.....

there was just a thread about this 2 days ago...

For emissions in general, make sure you have good spark plugs, distributor rotor, cap. Those are cheap things compared to other possibilities so check them out first.

what about your cat? it's been a long ass time since i've had tosmog. but i seem to remeber GTA needing a new cat before he passed

yea, when my nox was too high, what did was change my cat, and ran some fuel system cleaner through it.

check this site out for some help, it helped me when i failed

http://www.artsautomotive.com/thesmogstory.htm

Thank you all very much, I was going to change the spark plugs and cat, but I just wanted to check to see if I couldve missed something else. Ok here goes nothing.....

Oh that was me a few days ago.

I just replaced the cat and it passed but i got higher co2 readings, but who cares i passed.