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Discussion Starter · #1 ·
The tech passed the car visually, but it failed out the sniffer.
The car has:
2.3 whipple
accufab TB
60's
Tune
Bassani X w/ cats
Bassani catback

Anyone else fail out the sniffer. They do a 15mph and 25mph test. The worst part of the test was the NO's at 15 mph.
My test results:

@ 15 MPH / 2015 RPM:
HC - MAX=52, MEASURED=77
CO - MAX=.49, MEASURED=.10
NO - MAX=424, MEASURED=871

@ 25 MPH / 2200 RPM:
HC - MAX=36, MEASURED=54
CO - MAX=.46, MEASURED=.13
NO - MAX=711, MEASURED=695

My next plan of attack is to put my stock H pipe back on. I also want to tweak the tune w/ my PRP.
Any tuners out there know where to start???
 

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Yah, You Need A Smog Tune. You Can Change To Run However You Need It Too, I Would Not Run Very Hard With Smog Tune. Limp It There, Smog It, Put Normal Tune In After Smog, Drive Away.
 

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What plugs are you running? I heard that TR6's and most other copper plugs that are cooler may cause an issue with smog. When you go back put the factor motorcraft plugs back in it along with the smog tune.
 

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The tech passed the car visually, but it failed out the sniffer.
The car has:
...
Bassani X w/ cats
...
The tech let you walk. Those cats aren't legal in Ca and are what probably made you fail. Those cats aren't as good at cleaning emissions as stock cats. You can try tweaking the tune, but I think all you need are the stock cats.
 

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Discussion Starter · #7 ·
yeah, my NO is off the charts at 15mph. Looks like my cats weren't doing anything.

NO - MAX=424, MEASURED=871
 

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I dont know anyting bout the Cali smog but if you can, leave your car running before you smog it. Dont park and ket it cool while waiting in line. You want the cars engine to be nice and hot.
 

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1965 SPF 427 Cobra, & 2022 BMW M850
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CA Emissions Testing

I dont know anyting bout the Cali smog but if you can, leave your car running before you smog it. Dont park and ket it cool while waiting in line. You want the cars engine to be nice and hot.
MystiCobra is correct. When you smog in CA if you test before the CATS are up to operating temperature you will fail guaranteed. Once the CATS are up to temp no problem. Take the car for a few miles on the expressway at 55 and then go to the testing location and recheck, you'll be OK. I learned the hard way and the tech who did mine told me about the CATS not being up to temp. I did a quick spin on the expressway came back and passed with flying colors.

Ed
 

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The tech let you walk. Those cats aren't legal in Ca and are what probably made you fail. Those cats aren't as good at cleaning emissions as stock cats. You can try tweaking the tune, but I think all you need are the stock cats.
You're not supposed to change the cats or the location of the cats in California. That means no long tubes either. Shorties are ok if they have a CARB sticker but not worth the small increase you get.
Unless you know somebody who will turn a blind eye to a visual....
I know nothing, I seeeeeee nothing.
Jeff
 

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Discussion Starter · #11 ·
MystiCobra is correct. When you smog in CA if you test before the CATS are up to operating temperature you will fail guaranteed. Once the CATS are up to temp no problem. Take the car for a few miles on the expressway at 55 and then go to the testing location and recheck, you'll be OK. I learned the hard way and the tech who did mine told me about the CATS not being up to temp. I did a quick spin on the expressway came back and passed with flying colors.

Ed
yeah, i drove the car for a good while on the freeway to warm up the cats, so I'm sure they were up to temp...
 

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Before I get mine tested I re-install the stock H pipe, make sure that I have the Whipple paperwork that shows the California EO#, and I re-install the original 3.5 inch pulley. I have passed with no problem.
 

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If the cats don't fix it, this is where I would start looking:

NOx emissions are caused by high combustion temps. You might try retarding the timing a little in the areas where the smog tests are run.

The HCs make me suspect you may not actually be running at stoich in closed loop. Are your O2 sensors up to snuff? Do you have any exhaust leaks?
 

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Discussion Starter · #14 ·
If the cats don't fix it, this is where I would start looking:

NOx emissions are caused by high combustion temps. You might try retarding the timing a little in the areas where the smog tests are run.

The HCs make me suspect you may not actually be running at stoich in closed loop. Are your O2 sensors up to snuff? Do you have any exhaust leaks?
I'll try to compare my timing w/ the stock AMZ2 tune.

will faulty 02's always throw codes because I don't have any codes right now?
I believe I may have a few tiny exhaust leaks at some of the bassani connection points....
 

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Discussion Starter · #15 ·
Before I get mine tested I re-install the stock H pipe, make sure that I have the Whipple paperwork that shows the California EO#, and I re-install the original 3.5 inch pulley. I have passed with no problem.
I put on my 3.5 inch pulley too. I'll be putting back my stock H today. Are you runnng 60's, what tune did it pass w/?

Has anyone ever passed w/ aftermarket cats?
 

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doubleblack

I just had my 03 KB Cobra cheched/tuned and found out that my O2 sensors were "LAZY" (not responding very fast) !! Your AFR's are LEAN !! I have the SCT PRP too. Call me if you can use my help. <black2003cobra - deleted phone number for member privacy. Use PMs!>

Allen
 

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As mentioned above, reducing spark advance will reduce peak cylinder pressure, and hence, peak cylinder temps which reduces NOx formation.

AFR will also affect NOx emmisions, but peak emissions in ppm will actually occur at an equiv ratio of about 0.9. NOx drops off on either side of that.

CATs can certainly cause problems, as well.

But I'm also curious if you've deleted your EGR system. If you have, that could be your problem as well. NOx in ppm drops dramatically with an increased percent of exhaust gas recycled. (That's what this system is for, after all.) There really isn't any good technical reason to remove it.
 

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Discussion Starter · #18 ·
I just had my 03 KB Cobra cheched/tuned and found out that my O2 sensors were "LAZY" (not responding very fast) !! Your AFR's are LEAN !! I have the SCT PRP too. Call me if you can use my help. <black2003cobra - deleted phone number for member privacy. Use PMs!>

Allen
Allen, you still have that same KB'd cobra when we met back in 03, I thought you got rid of it...did you ever have to smog it yet?

anyhow, thanks for the response...I'm going to do a couple other things before I buy new 02 $ensors...I'll get them when I get desperate...the tech in poway will give me $20 off everytime I have to retest...so not terribly worried yet...Initially I was more worried w/ visual but passed w/ flying colors...
 

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Discussion Starter · #19 ·
As mentioned above, reducing spark advance will reduce peak cylinder pressure, and hence, peak cylinder temps which reduces NOx formation.

AFR will also affect NOx emmisions, but peak emissions in ppm will actually occur at an equiv ratio of about 0.9. NOx drops off on either side of that.

CATs can certainly cause problems, as well.

But I'm also curious if you've deleted your EGR system. If you have, that could be your problem as well. NOx in ppm drops dramatically with an increased percent of exhaust gas recycled. (That's what this system is for, after all.) There really isn't any good technical reason to remove it.
black, i'm going to compare my timing curves to a bone stock AMZ2 calibrating and see if there's much of a difference, if so i'll adjust accordingly...my car has all the EGR equipment..my NOx failed miserably at 15mph but at 25mph I actaully barely passed, it seems the lower rpms is where I had the problems...
 

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black, i'm going to compare my timing curves to a bone stock AMZ2 calibrating and see if there's much of a difference, if so i'll adjust accordingly...my car has all the EGR equipment..my NOx failed miserably at 15mph but at 25mph I actaully barely passed, it seems the lower rpms is where I had the problems...
My son and I went deep into this trying to get his Honda B16A race engine to pass. They test with the dyno at significantly higher load at 15MPH than they do at 25MPH. That is why you are seeing higher NOx at 15MPH.

I'd try cats first, and then check the timing. Also, if you are too lean you can drive the NOx up, but if the O2 sensor feedback is working you should not be lean since the tests are run closed loop. Slightly failing the HCs make me think you may actually be running rich, which could happen if the O2 feedback is compromized.

The things I know of that can affect proper O2 feedback are bad sensors and exhaust leaks. You could probably see "lazy" O2 sensors in the O2 voltage logs. A good shop should have a smoke tester. That is a really good way of finding exhaust leaks.

BTW, we never were able to get the Honda to pass smog, but that was due to nearly a 12:1 compression ratio. But we put down over 100hp/liter to the wheels NA. :)

The Honda finally got a stock Integra motor for its smog test.
 
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