fail ca smog, nox too high, need help
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fail ca smog, nox too high, need help
Car is a bone stock 95 Acura Integra 4 door LS. This car passed smog 2 yrs ago with flying colors. Had readjusted the valves and re-shoot the timming couple months after the smog test, drove it like that without replacing anything ever since, only oil change every 3-4K miles. Now this car has bout 250+K miles and it eats quite a bit of oil, but does not smoke, pings a little on hard acceleration( might be too advanced when it had the timming re-shoot) but still runs very good.
So recently before this new smog test, I had change the old spark plugs and found out that the tip of the spark tip had kinda melted in a way, not extremely just a bit slanted. It was somewhat getting poor gas mileage on small streets, but if in highway it still gets decent mileage around 350+miles full tank. So I replace the old spark plugs with new ngk platinum ones,(I know I didn't really need to use platinum spark plugs but got it for a good price).
So everything seemed gravy and I took it in for a smog test today, it pass the 25mph test but failed the 15mph test because Nox was high.
here were the results for 15mph test
please note: MAX=Maximum Allowable Emissions / AVE= Average Emission for passing vehicles / MEAS= Amount measured
CO2 MEAS 14.07
--------------------
O2 MEAS 0.16
--------------------
HC (PPM)
MAX 90
AVE 41
MEAS 59
--------------------
CO
MAX 0.54
AVE 0.12
MEAS 0.28
---------------------
NO (PPM)
MAX 711
AVE 150
MEAS 0780
---------------------
Results FAIL
Results for 25mph test
CO2 MEAS 14.09
--------------------
O2 MEAS 0.11
--------------------
HC (PPM)
MAX 43
AVE 25
MEAS 43
--------------------
CO
MAX 0.53
AVE 0.10
MEAS 0.22
---------------------
NO (PPM)
MAX 754
AVE 112
MEAS 0521
---------------------
Results PASS
I did some search online and found that Nox was due to having too much heat in the combustion chamber, causing a lean mixture perhaps. Kinda makes sense to me cause remember my old spark plug tip was melted in a way.
Im kinda comming to the conclusion that it could simply just be that my timming is a little too advanced, but i wanted to post this here to get second opinions on what i could or should check/replace before taking it back in, cause it kinda hurts to give away 42 dollar each time you fail lol.......
So recently before this new smog test, I had change the old spark plugs and found out that the tip of the spark tip had kinda melted in a way, not extremely just a bit slanted. It was somewhat getting poor gas mileage on small streets, but if in highway it still gets decent mileage around 350+miles full tank. So I replace the old spark plugs with new ngk platinum ones,(I know I didn't really need to use platinum spark plugs but got it for a good price).
So everything seemed gravy and I took it in for a smog test today, it pass the 25mph test but failed the 15mph test because Nox was high.
here were the results for 15mph test
please note: MAX=Maximum Allowable Emissions / AVE= Average Emission for passing vehicles / MEAS= Amount measured
CO2 MEAS 14.07
--------------------
O2 MEAS 0.16
--------------------
HC (PPM)
MAX 90
AVE 41
MEAS 59
--------------------
CO
MAX 0.54
AVE 0.12
MEAS 0.28
---------------------
NO (PPM)
MAX 711
AVE 150
MEAS 0780
---------------------
Results FAIL
Results for 25mph test
CO2 MEAS 14.09
--------------------
O2 MEAS 0.11
--------------------
HC (PPM)
MAX 43
AVE 25
MEAS 43
--------------------
CO
MAX 0.53
AVE 0.10
MEAS 0.22
---------------------
NO (PPM)
MAX 754
AVE 112
MEAS 0521
---------------------
Results PASS
I did some search online and found that Nox was due to having too much heat in the combustion chamber, causing a lean mixture perhaps. Kinda makes sense to me cause remember my old spark plug tip was melted in a way.
Im kinda comming to the conclusion that it could simply just be that my timming is a little too advanced, but i wanted to post this here to get second opinions on what i could or should check/replace before taking it back in, cause it kinda hurts to give away 42 dollar each time you fail lol.......
Last edited by jdmcivic2fast; 10-18-2011 at 03:48 PM.
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Re: fail ca smog, nox too high, need help
it jumps around from 16-18* as far as i can see, i redid the timming and now its right at 16* the red line or middle line, this is with a wire jumping the CEL plug, if i take out the wire from the CEL plug then it sits at 14*. this is correct right?
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Re: fail ca smog, nox too high, need help
If you just want to cheat the test a little.
or
Both lower combustion temps, which reduces NOx emissions.
Retarding the timing can change the HC emissions, but that shouldn't be much of an issue for this car.
or
Both lower combustion temps, which reduces NOx emissions.
Retarding the timing can change the HC emissions, but that shouldn't be much of an issue for this car.
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Re: fail ca smog, nox too high, need help
lol, have seen many people still fail with those stuff, but maybe because they are way over the limit on the smog test, it seems like my car just barely failed the nox by about 70 more, do you think your formulas you show me will work?
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Re: fail ca smog, nox too high, need help
Brought HC down enough to get a foul running 88 Civic to just pass. Brought NOx down enough to pass on a Spitfire missing it's smog pump and EGR.
That's the extent of my personal experience though.
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Re: fail ca smog, nox too high, need help
do i just pour the whole bottle of g2p in my tank?
#14
Re: fail ca smog, nox too high, need help
Seriously man, I feel your pain. Dealing with NY's emissions bullshit damn near drives me to violence, I can only imagine what you guys go though. If NY ever adopts SMOG testing (which wouldn't come as a surprise to anyone) I'm moving to Vermont.
Out of curiosity, why did you advance the timing in the first place?
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Re: fail ca smog, nox too high, need help
Seriously man, I feel your pain. Dealing with NY's emissions bullshit damn near drives me to violence, I can only imagine what you guys go though. If NY ever adopts SMOG testing (which wouldn't come as a surprise to anyone) I'm moving to Vermont.
Out of curiosity, why did you advance the timing in the first place?
Out of curiosity, why did you advance the timing in the first place?
anyhow, i was trying to set the timming at 16 but it jumps around alot so i think i set it advanced by acciendent.
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Re: fail ca smog, nox too high, need help
I followed the directions on the bottle for my Civic. If my memory serves (and it's been a few years) you put the whole bottle into the tank, drive enough to burn half the tank, fill the tank back up, and go test.
It's mostly alcohol, which doesn't produce as much HC when it burns, which is what helps clean up the exhaust readings.
For the Spitfire, since the NOx was absurdly high (lacking the necessary smog equipment, raised compression, and a performance cam), I dumped one bottle in, drove for half a tank, dumped another bottle in, filled the tank, then had it tested. I should have done the correct thing and put a modern 3 stage cat on it, since the older 2 way ones don't break down NOx.
Alcohol burns cooler, so it reduces NOx.
That's why ISO Heet can be used, as it's a bottle of alcohol intended to help keep gas from freezing in super cold climates.
The car will run leaner with these additives in the gas. Don't push the car until you clear the tank (run to near empty, refill without additive).
It's mostly alcohol, which doesn't produce as much HC when it burns, which is what helps clean up the exhaust readings.
For the Spitfire, since the NOx was absurdly high (lacking the necessary smog equipment, raised compression, and a performance cam), I dumped one bottle in, drove for half a tank, dumped another bottle in, filled the tank, then had it tested. I should have done the correct thing and put a modern 3 stage cat on it, since the older 2 way ones don't break down NOx.
Alcohol burns cooler, so it reduces NOx.
That's why ISO Heet can be used, as it's a bottle of alcohol intended to help keep gas from freezing in super cold climates.
The car will run leaner with these additives in the gas. Don't push the car until you clear the tank (run to near empty, refill without additive).
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Re: fail ca smog, nox too high, need help
I followed the directions on the bottle for my Civic. If my memory serves (and it's been a few years) you put the whole bottle into the tank, drive enough to burn half the tank, fill the tank back up, and go test.
It's mostly alcohol, which doesn't produce as much HC when it burns, which is what helps clean up the exhaust readings.
For the Spitfire, since the NOx was absurdly high (lacking the necessary smog equipment, raised compression, and a performance cam), I dumped one bottle in, drove for half a tank, dumped another bottle in, filled the tank, then had it tested. I should have done the correct thing and put a modern 3 stage cat on it, since the older 2 way ones don't break down NOx.
Alcohol burns cooler, so it reduces NOx.
That's why ISO Heet can be used, as it's a bottle of alcohol intended to help keep gas from freezing in super cold climates.
The car will run leaner with these additives in the gas. Don't push the car until you clear the tank (run to near empty, refill without additive).
It's mostly alcohol, which doesn't produce as much HC when it burns, which is what helps clean up the exhaust readings.
For the Spitfire, since the NOx was absurdly high (lacking the necessary smog equipment, raised compression, and a performance cam), I dumped one bottle in, drove for half a tank, dumped another bottle in, filled the tank, then had it tested. I should have done the correct thing and put a modern 3 stage cat on it, since the older 2 way ones don't break down NOx.
Alcohol burns cooler, so it reduces NOx.
That's why ISO Heet can be used, as it's a bottle of alcohol intended to help keep gas from freezing in super cold climates.
The car will run leaner with these additives in the gas. Don't push the car until you clear the tank (run to near empty, refill without additive).
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Re: fail ca smog, nox too high, need help
Don't use a higher octane than what the car is deigned for though.
Does the LS engine have an EGR? If so, cleaning out the carbon that builds up inside of it could help reduce NOx, if it's chocking flow now.
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Re: fail ca smog, nox too high, need help
no egr, what about seafoam? can i use that to clean the carbon build up in the chamber? would that be ideal?
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Re: fail ca smog, nox too high, need help
I don't trust seafoam and similar products. It just screams "snake oil" to me. Changing what is burning during the test itself seems like a more productive way to change emissions readings, to me at least.
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