WEll I have 2241 ppm on nox with an allowable 889

so I am a gross polluter, everything else is fine.

Is high nox due to high combustion temp?

Its a rebuilt engine with about 2k on it, new spark plugs with engine, new O2, 300 miles, My cat is about 2 years old, it was on my car when I was burning alot of oil, could this have killed it? and I get about 33 mpg.

I am going to try replacing the fuel filter, and radiator.

Any other ideas?

 

1- air filter
2- oil change
3- Retard ignition timing 4 degrees ( A freind from Honda who specializes in emmisions showed me that)

 

Nox is usually your Cat. or EGR Valve. Check both.

 

Well I don't have an EGR valve, but I could try the cat..

oil change was 500 miles ago..
and I will try cleaning my K&N filter..

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by xvracing &raquo;</TD></TR><TR><TD CLASS="quote">
3- Retard ignition timing 4 degrees ( A freind from Honda who specializes in emmisions showed me that)</TD></TR></TABLE>

You need stock timing to pass smog in CA

 

You get a few degrees to be off.. 14 is stock I believe. I timed in at 16 deg

so I was a bit advanced, but 2 degrees is not much..

 

ive seen a lot of cars that were burning oil kill the cat. with a new o2 sensor and motor, i would only have to guess that the cat is dead. replace that.. it should lower down the emissions, and gain some more power. good luck

 

NoX is caused by high combustion chamber temps.

What are the numbers you got for the other test readings?

If your cat was dead it would fail HC's.

You get high NoX from either having too much compression or from running lean. A lazy O2 is very common when you have high NoX.

 

Not sure about high compression, I have a Single cam ZC block, and a 93 civic head ( it came that way rebuilt from K-watanabe).

and the 02 I just replaced 2 weeks ago

I think I was running 89 octane

My numbers
at 15mph
HC:107, 147 max CO: .68, .88 max NO:2241, 889 max

at 25mph
HC:30, 122 max CO: .30, .78 max NO:973, 828 max

 

That cat definitely isn't happy. It's not dead, but it's not good. Your HC's and CO's are pretty high. How is your PCV doing?

If you go to a muffler shop they should be able to test the cat to make sure it's lighting up properly. They put it up on the lift and use a thermometer to test the heat going into the cat as well as exiting the cat. If the cat isn't lighting up the they can tell you about it rather than you just replacing it and HOPING it works. If they do (probably will) replace the cat, then make sure you do about 50 miles on the freeway before taking it in for test. It takes a little bit to get the cat to start working properly.

Use that octane again. You don't want to run high octane. Lower octane burns more completely than the high octane.

 

well here is my game plan...

replace cat, replace fuel filter, and pcv valve...

the old seems to work fine.. its just a one way valve yeah..

 

i just got done posting something on this section about denatured alcohol. stuff really works and the person that i told this to posted his before and after results. you can get it from home depot. let me find the thread and ill copy and paste. i knew we should have made it a sticky.
kris
hopefully the link works
https://honda-tech.com/zerothread?id=587799
im also logged in on my brothers account. im suprfast

 

Yea like the others have said NOX is caused by really hot combustion temps. My SOHC ZC failed as well because of the high NOX. What i did was retard my timing 2 degrees (so it was at 14degrees), turned up my fuel pressure 2-5psi (i dont remember how much exactly), and put some of General Motors "top end cleaner" in the gas tank when i filled up. The cleaner will clean out any carbon build up that u might have. Carbon build up causes excessive heat in the combustion chamber. I did these things on my car and i barely passed. BTW, u will want to run a full tank with the cleaner in there until its emtpy, then refill with gas and go test. Also, I richened my mixture to make sure i wasnt running too lean, and because my CO and HC readings were fairly low. Those HC and CO readings did come up a little higher after i turned up the PSI but not nearly enough to fail me.

 

How much denatured alchohol would I add per gallon?

I have heard of people doin this before..but no one I knew..

 

hey Lee this is what i keep failing smog on, my numbers for hc, and cos are really low, but the nox is failing, not as bad as yours, i have a new cat, new air filter, about 10 months on my fuel fiter. i changed cap, rotor, plugs, wires, and i set my ignition timing to 12 degrees (you can be +/- 2*) and i still failed, not as bad, i think my injectors are just nasty. The motor that i pulled the mani from burned oil badly and it gunked up the injectors and intake manifold but i didnt bother with it. We will see how the new motor runs and if that doesnt work i really gotta pull something out of my ***.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by matt j &raquo;</TD></TR><TR><TD CLASS="quote">hey Lee this is what i keep failing smog on, my numbers for hc, and cos are really low, but the nox is failing, not as bad as yours, i have a new cat, new air filter, about 10 months on my fuel fiter. i changed cap, rotor, plugs, wires, and i set my ignition timing to 12 degrees (you can be +/- 2*) and i still failed, not as bad, i think my injectors are just nasty. The motor that i pulled the mani from burned oil badly and it gunked up the injectors and intake manifold but i didnt bother with it. We will see how the new motor runs and if that doesnt work i really gotta pull something out of my ***.</TD></TR></TABLE>

Your injectors would have to be clogged because that is one of the symptoms with high NOX. A lean condition causes the motor to run hotter than normal.