I took my gf's 90 Integra to get smogged today. Didn't pass, Kind of wondering on what it could be. Here are my numbers:

15MPH:
HC:
Max: 121
Meas:48

CO:
Max: .76
Meas: .21

NO:
Max: 807
Meas: 899

25 MPH
HC:
Max:96
Meas:39

CO:
Max: .65
Meas: .22

NO:
Max: 746
Meas: 723

So as you can see it barely fails. If anybody has any input I would greatly appreciate it. Thx in advance

 

get a new cat

 

check for vaccum leaks. High nox means your mixture is too lean. make sure timing is set properly as well.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fasteddy91 &raquo;</TD></TR><TR><TD CLASS="quote">get a new cat</TD></TR></TABLE>Pretty much what i've been thinking along w/ a new o2 sensor

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 99Geeezer &raquo;</TD></TR><TR><TD CLASS="quote">check for vaccum leaks. High nox means your mixture is too lean. make sure timing is set properly as well.</TD></TR></TABLE>Timing is dead on, I'll see about the vacum leaks.

Would a new pcv valve help as well???

And thank you for your responses

 

with failing by that little, you shouldnt have to replace your cat, especially since the only part you failed was nox at 15

 

So it might be something small??

 

bump for more info

 

I just smoged mine today. Things to keep a eye on before testing (What i do)

1. Tune up (Plugs, Wires, Cap, etc)
2. Check O2 sensors, and cat life
3.PCV value could be the probelm (take it off Shake it and if you hear a sound its ok, if not its bad)
4. I use Lucas in my Tank to keep it clean.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BKKloppenborg &raquo;</TD></TR><TR><TD CLASS="quote">I just smoged mine today. Things to keep a eye on before testing (What i do)

1. Tune up (Plugs, Wires, Cap, etc)
2. Check O2 sensors, and cat life
3.PCV value could be the probelm (take it off Shake it and if you hear a sound its ok, if not its bad)
4. I use Lucas in my Tank to keep it clean.</TD></TR></TABLE>Yeah pretty much what I'm going to do when I take it back, As far as the cat, Is there a way to tell that it's bad???

 

I'd use a higher octane fuel that should do it....

 

high nox is a lean mixture usually. high combustion chamber temps in general.

1. try advancing timing to around 15 deg btdc.. which is still withing the acceptable limits
2. check fuel filter/pressure
3. check coolant... try mixing closer to the water side.
4. higher octane fuel since it burns slower and help cool cumbustion chamber (mentioned earlier)
5. Test O2 sensor. maybe just replace it since it isn't heated and will be cheap.
6. go to your local parts store and look for a product called "HEET" its a fuel anti-freeze. throw a bottle in at half tank and drive around for a few miles.

this is all i can think of for right now... high NOX is common but not impossible to remidy.

 

Thanks bro, i'll look into that

 

Before going to smog, drive around for 20 minutes or so to get the cat hot. Also what was mentioned above...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Tarmac Junkie &raquo;</TD></TR><TR><TD CLASS="quote">Before going to smog, drive around for 20 minutes or so to get the cat hot. Also what was mentioned above...</TD></TR></TABLE>

I second that! Drive it for awhile and get your engine super hot (cat also). Also, each visit can vary in measuring NO or HC. Maybe next time you go you'll pass witout having to do much. Good luck

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JETSPD1477 &raquo;</TD></TR><TR><TD CLASS="quote">high nox is a lean mixture usually. high combustion chamber temps in general.

1. try advancing timing to around 15 deg btdc.. which is still withing the acceptable limits
2. check fuel filter/pressure
3. check coolant... try mixing closer to the water side.
4. higher octane fuel since it burns slower and help cool cumbustion chamber (mentioned earlier)
5. Test O2 sensor. maybe just replace it since it isn't heated and will be cheap.
6. go to your local parts store and look for a product called "HEET" its a fuel anti-freeze. throw a bottle in at half tank and drive around for a few miles.

this is all i can think of for right now... high NOX is common but not impossible to remidy.
</TD></TR></TABLE>

Please help me understand how advancing the timing is gonna bring down nox?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by FTP racing &raquo;</TD></TR><TR><TD CLASS="quote">

Please help me understand how advancing the timing is gonna bring down nox?</TD></TR></TABLE>

my mistake. i meant retarding...

 

no worries!

 

There's some stuff at your local auto parts store called Guaranteed To Pass (GTP)

It works~