Failed Smog test (high HC, CO, and NOx) - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

ViciousCesar! · 03-13-2012, 02:34 PM

I took my car to get smogged and it failed miserably.

Here's what it read...

Car: 1990 stock KA24e 240sx

15mph:
HC max: 85 , measured: 101
CO max: .54 , measured: .75
NO max: 565 , measured: 655

25mph
HC max: 67 , measured: 104
CO max: .45 , measured: 1.43
NO max: 522 , measured: 690

So those were the numbers, can anyone point me in the right direction just by reading that?

Any and all help is appreciated.

Mitsubayati · 03-13-2012, 03:33 PM

That wasn't a miserable fail haha.

What's the condition of the catalytic converter? Are there any leaks in your exhaust system? Any aftermarket exhaust components or engine modifications. Any check engine light codes? When did you smog it last? Did it pass then? Do you know the numbers for that run as well?

andisan · 03-13-2012, 03:46 PM

Yeah those numbers are not that bad, Mine where crazy high that they put the sniffer on and right away the guy told me NOPE!!!! that he wouldnt even take the car in

so I checked all the smog parts and cleaned them good and i also had a bad injector too, which was part of the problem and i had a couple of cloged parts that where not working right.

Pandadub92 · 03-13-2012, 03:50 PM

smogged my single cam and it barely passed but it had 260K on it and the original cat and exhaust. i just made sure i changed my filter, oil, my plugs, cap and rotor and it seemed to help it pass. still a weak cat tho

Pandadub92 · 03-13-2012, 03:58 PM

1989 stock KA24E S13

15mph:
HC max: 83 , measured: 83
CO max: .53 , measured: .27
NO max: 559 , measured: 231

25mph
HC max: 65 , measured: 65
CO max: .44 , measured: 30
NO max: 516 , measured: 435

ViciousCesar! · 03-13-2012, 04:14 PM

Quote:

Originally Posted by Mitsubayati

That wasn't a miserable fail haha.

What's the condition of the catalytic converter? Are there any leaks in your exhaust system? Any aftermarket exhaust components or engine modifications. Any check engine light codes? When did you smog it last? Did it pass then? Do you know the numbers for that run as well?

No engine mods or aftermarket exhaust components. The cat seems to have been replaced by the previous owner when he replaced the original exhaust. The car passed smog since then (about 19 months ago). There is a leak at the gasket to the cat from scrapping. Check engine light is not on. I don't have the numbers freom the last test on hand.

Zed Nismo · 05-07-2012, 02:20 AM

I would suggest fixing the leak at the cat and also make sure you have the heat shield on the exhaust manifold and the mid pipe going to the cat (Mid pipe heat shield has a fiberglass insulation in the middle). The heat has to be contained all the way to the catalytic converter for the converter to do it's job properly. That's why the heat shields were there in the first place as well. That helped me pass with no problems. I had a worst failure, went to smog 4 times before it actually passed.

godrifttoday · 05-07-2012, 06:53 AM

I would suggest paying someone under the table to pass smog! What's the going rate like 140 or so?

Nikeboy355 · 05-07-2012, 08:41 AM

Illegal smog is not going to work in California for much longer...
We need to just get the cars to pass correctly now...

If there is no CEL and all leaks are fixed, I would consider changing the catalytic converter and spark plugs for a total of about $150... And try testing again... I'm pretty sure that it will be enough...

In California this year, they have added more restrictions to get older cars off the road... It's getting more and more strict...

bladetech8 · 05-07-2012, 10:10 PM

^ I beg to differ.. If I'm waving $250+ in front of some smog dude's face, I'll be hard pressed to think he won't do anything but guarantee to pass me regardless of what bureaucratic bullshit is going on with the California BAR or EPA.. Money speaks and some things are just worth the calculated risk..

Tantwoforty · 05-08-2012, 05:48 AM

i dont think your sposta tell people to break the law on here.
Plus if its stock it should pass anyway, try seafoam, it helps clean out the egr and iacv unless you want to pull them off and actually clean them.
Are you sure there's actually a cat in there? i see alot of hollowed out ones..
maybe clean the 02, make sure its super hot before you test it. i had to get a new cat for mine back when it was stock and it passed
best of luck man!

bladetech8 · 05-08-2012, 06:30 PM

lol I believe we're all breaking the LAW in one way or another, driving modified 240's on a daily basis. Being low is technically illegal, but no one's fussing around in the "how to make your car scraping low" threads

But yeah smog stuff is kinda iffy or what not, so that conversation ends here.

godrifttoday · 05-08-2012, 10:50 PM

damm u pay 250? thats a grip...

bladetech8 · 05-09-2012, 01:40 PM

haha not really. It was just an exaggeration to make a point..

03-13-2012, 02:34 PM	#1
ViciousCesar! Zilvia FREAK! Join Date: May 2009 Location: Doomstadt, FL Posts: 1,280 Trader Rating: (8) Feedback Score: 8 reviews	Failed Smog test (high HC, CO, and NOx) I took my car to get smogged and it failed miserably. Here's what it read... Car: 1990 stock KA24e 240sx 15mph: HC max: 85 , measured: 101 CO max: .54 , measured: .75 NO max: 565 , measured: 655 25mph HC max: 67 , measured: 104 CO max: .45 , measured: 1.43 NO max: 522 , measured: 690 So those were the numbers, can anyone point me in the right direction just by reading that? Any and all help is appreciated.

03-13-2012, 03:33 PM	#2
Mitsubayati Zilvia FREAK! Join Date: Aug 2007 Location: The Dro Posts: 1,424 Trader Rating: (18) Feedback Score: 18 reviews	That wasn't a miserable fail haha. What's the condition of the catalytic converter? Are there any leaks in your exhaust system? Any aftermarket exhaust components or engine modifications. Any check engine light codes? When did you smog it last? Did it pass then? Do you know the numbers for that run as well? __________________

03-13-2012, 03:46 PM	#3
andisan Nissanaholic! Join Date: Oct 2007 Location: Lompoc CA 805!!!! Age: 41 Posts: 2,063 Trader Rating: (12) Feedback Score: 12 reviews	Yeah those numbers are not that bad, Mine where crazy high that they put the sniffer on and right away the guy told me NOPE!!!! that he wouldnt even take the car in so I checked all the smog parts and cleaned them good and i also had a bad injector too, which was part of the problem and i had a couple of cloged parts that where not working right. __________________

05-07-2012, 06:53 AM	#8
godrifttoday Post Whore! Join Date: Jan 2004 Location: los angeles Age: 41 Posts: 3,120 Trader Rating: (82) Feedback Score: 82 reviews	I would suggest paying someone under the table to pass smog! What's the going rate like 140 or so? __________________ NEED Bolt kits for your car?

05-07-2012, 08:41 AM	#9
Nikeboy355 Zilvia Addict Join Date: Mar 2004 Location: Los Angeles, CA Age: 45 Posts: 734 Trader Rating: (0) Feedback Score: 0 reviews	Illegal smog is not going to work in California for much longer... We need to just get the cars to pass correctly now... If there is no CEL and all leaks are fixed, I would consider changing the catalytic converter and spark plugs for a total of about $150... And try testing again... I'm pretty sure that it will be enough... In California this year, they have added more restrictions to get older cars off the road... It's getting more and more strict... __________________ http://respectvolkracing.blogspot.com/

03-13-2012, 03:50 PM	#4
Pandadub92 Join Date: Jul 2011 Location: Corona, CA Age: 33 Posts: 14 Trader Rating: (0) Feedback Score: 0 reviews	smogged my single cam and it barely passed but it had 260K on it and the original cat and exhaust. i just made sure i changed my filter, oil, my plugs, cap and rotor and it seemed to help it pass. still a weak cat tho

03-13-2012, 03:58 PM	#5
Pandadub92 Join Date: Jul 2011 Location: Corona, CA Age: 33 Posts: 14 Trader Rating: (0) Feedback Score: 0 reviews	1989 stock KA24E S13 15mph: HC max: 83 , measured: 83 CO max: .53 , measured: .27 NO max: 559 , measured: 231 25mph HC max: 65 , measured: 65 CO max: .44 , measured: 30 NO max: 516 , measured: 435

05-07-2012, 02:20 AM	#7
Zed Nismo Leaky Injector Join Date: Dec 2010 Location: Manteca, CA Age: 32 Posts: 63 Trader Rating: (0) Feedback Score: 0 reviews	I would suggest fixing the leak at the cat and also make sure you have the heat shield on the exhaust manifold and the mid pipe going to the cat (Mid pipe heat shield has a fiberglass insulation in the middle). The heat has to be contained all the way to the catalytic converter for the converter to do it's job properly. That's why the heat shields were there in the first place as well. That helped me pass with no problems. I had a worst failure, went to smog 4 times before it actually passed.

05-07-2012, 10:10 PM	#10
bladetech8 Zilvia Addict Join Date: Jun 2010 Location: Southern California (LA/OC) Posts: 828 Trader Rating: (32) Feedback Score: 32 reviews	^ I beg to differ.. If I'm waving $250+ in front of some smog dude's face, I'll be hard pressed to think he won't do anything but guarantee to pass me regardless of what bureaucratic bullshit is going on with the California BAR or EPA.. Money speaks and some things are just worth the calculated risk..

05-08-2012, 05:48 AM	#11
Tantwoforty Nissanaholic! Join Date: May 2009 Location: Riverside ca Age: 35 Posts: 1,890 Trader Rating: (20) Feedback Score: 20 reviews	i dont think your sposta tell people to break the law on here. Plus if its stock it should pass anyway, try seafoam, it helps clean out the egr and iacv unless you want to pull them off and actually clean them. Are you sure there's actually a cat in there? i see alot of hollowed out ones.. maybe clean the 02, make sure its super hot before you test it. i had to get a new cat for mine back when it was stock and it passed best of luck man!

05-08-2012, 06:30 PM	#12
bladetech8 Zilvia Addict Join Date: Jun 2010 Location: Southern California (LA/OC) Posts: 828 Trader Rating: (32) Feedback Score: 32 reviews	lol I believe we're all breaking the LAW in one way or another, driving modified 240's on a daily basis. Being low is technically illegal, but no one's fussing around in the "how to make your car scraping low" threads But yeah smog stuff is kinda iffy or what not, so that conversation ends here.

05-08-2012, 10:50 PM	#13
godrifttoday Post Whore! Join Date: Jan 2004 Location: los angeles Age: 41 Posts: 3,120 Trader Rating: (82) Feedback Score: 82 reviews	damm u pay 250? thats a grip... __________________ NEED Bolt kits for your car?

05-09-2012, 01:40 PM	#14
bladetech8 Zilvia Addict Join Date: Jun 2010 Location: Southern California (LA/OC) Posts: 828 Trader Rating: (32) Feedback Score: 32 reviews	haha not really. It was just an exaggeration to make a point..