okay i need to take a smog test like within the next month or so..
i took it to get a pretest done to it
hc and co numbers a great....exactly where they need to be
nox level at 15mph is at 1900 where it should be around 800 or 1000
the guy that did the pretest said o2 sensor or cat..
but i thought i just changed those two in the past two years.
so okay, i give in and change the two..brand new, change the plugs also
and i wipe down my bumper cuz within a week my bumper is black so okay, everytime i changed something i clean the bumper and take a look the next day...and it has black specks so i get frustrated and move to the next thing i can change or adjust.

yesterday i had the timing adjusted back to factory spec and cleaned my bumper. it was advanced. i got to work and the black specks are back and i'm very frustrated..

i just poured in valvoline complete fuel system treatment and cleaned my bumper once again...

help me figure it out..i dont wanna have to go under the table and pay 300 to pass it...i have a header but that shouldnt matter one bit. and all the vaccumm lines are all intacted.

i also checked for resistance on all the fuel injectors and they are within factory spec. we also noticed the injector seals might need replacing, would that be a slight cause? it was slightly wet on the manifold around the injectors.

and also pulled the pcv valve off, did the test in the fsm where it tells u to pinch the vaccum line and it clicked so it works i'm guessing. so i pull it out and its all gunky so i wipe it down and shoved it back in its hole.

the car is a 1988 integra odb0 dohc d16a3 (zc equivalent)
with a lightspeed header (carb numbered)
stock intake with k&n drop in filter.
it doesnt have a egr valve that i've been reading on honda-tech that others are cleaning out

15mph pretest showed
HC at 64ppm
CO at 0.1%
CO2 at 9.6%
O2 at 7.5%
NOx at 1908ppm

i'm very stuck
HELLPPPPP

 

maybe a cracked manifold? or some gasket around the intake side? seems like an air leak is getting you on that. Also check the plugs and see if any of them is different than the others. Maybe a clogged plug is giving less fuel than you need.

 

I had hign Nox numbers and my intake manifold wasn't sealed right. May need to consider that, besides you can clean out the manifold too.

 

was this done on a two speed ide test???

 

One of the biggest contributers to high NOx is a bad oxygen sensor. You might want to replace this. Also, a bad or clogged cat can cause high NOx.

 

Try retarding your timing(more) and using higher octane fuel. High NoX is cause by high combustion chamber temps. Good luck.

Phil