SMOG Legality - Testing, Tuning, Etc.

Post by **Nismo_Freak** » Sun Jul 17, 2005 2:36 am

If you live in a state where they do Smog testing you will never legally pass the inspection with an SR. The engine was not tested, and is not on the EPA's list of engines.

However, the SR CAN pass the sniffer test quite easily. You will need a functioning cat, along with a relatively stock engine setup.

In a perfectly running combustion cycle we decompose fuel (aka ignite) and form products with the air mixture. These products are H20 (water), CO (Carbon Monoxide), N0x (Oxides of Nitrogen), CO2 (Carbon Dioxide), HC's (uncombusted fuel), 02 (elemental oxygen), N2 (elemental Nitrogen), and H2 (elemental Hydrogen).

Excessive timing, boost, cooled air, airflow can create high amounts NOx which is what I see alot of people failing. This is due to the required high temperatures in which NOx is formed. Reducing the combustion temps will reduce the NOx pollution, which is why the EGR system was created.

Some setups will run into HC failures, where they are running rich in the lower RPM due to excessive fuel pressure (common to stock FPRs w/ hi-flo pumps). A S-AFC can be used to reduce the injector pulsewidths down to a moderated level to reduce the HC's. Be forwarned this can also increase NOx emissions when you lean out the mixture.

CO failures tend to be engines that are running too rich. CO is formed when the fuel hydrocarbons break down and are in a Oxygen deficient locality (meaning the mixture is rich). This translates to less CO2, and more CO emissions. Typically high CO's are related with relatively high HC's as well.

For the visual testing you need to find a "friendly" testing place, if you understand what I am getting at

Post by **modified** » Mon Mar 06, 2006 5:50 pm

So, will the sr pass a onboard diagnostic test?

Post by **Onizuka** » Mon Mar 06, 2006 6:01 pm

Absolutly not, but that only concerns people with cars manufactured 96 and newer. That can also be gotten around (especially if your not in california), if you can find the right people to go to.

I have a "friend" who found someone to stick a stock oldsmobile on the sniffer machine in place of his black sr-powered s13 coupe at no extra cost. You just have to find someone that has an equal love of all things automotive

Post by **modified** » Mon Mar 06, 2006 7:25 pm

That why i ask, its 98. Any way to have the motor cleared for street use, from DOT, EPA?

Post by **s13_drftone** » Sun Mar 12, 2006 9:51 pm

no you just got to pay the price of $200

Post by **jjh** » Sun May 14, 2006 2:22 pm

nice for locking the thread, i was wondering in nj has smog testing.

Post by **drifter_for_life06** » Sun May 14, 2006 2:31 pm

for the guys in PA..if i get a hi-flow cat on my 92 S13, i should be good right?

i got an emissions exempt sticker in March, but that was b/c i had less than 5k miles on the odo. since the last inspection.

Post by **hazw8st** » Mon May 15, 2006 4:28 pm

s13_drftone wrote:no you just got to pay the price of $200

Try again, back door smog for an SR20DET for 2 bills..... we're in 2006, these smog techs are asking $400 bucks here in SoCal.....

Post by **nistangclan727** » Sat May 27, 2006 11:37 pm

would an sr pass in oh

Post by **XFD** » Mon Jun 05, 2006 5:45 pm

Is there a site that lists all the smog states and what forms of testing they do? Googling for "Smog States" and variants returns rather irrelevent results. (I'm in Oregon)

Post by **drifter_for_life06** » Tue Jun 06, 2006 5:39 am

i was able to go to state.pa.us (obviously not the same link if you dont live in PA) and found somewhere on there what tests they run on certain year vehicles

just plug in your info and BAM,there ya go

Post by **nistangclan727** » Wed Jun 07, 2006 11:22 am

what states would a stok sr pass

Post by **hazw8st** » Mon Jun 12, 2006 2:41 pm

modified wrote:That why i ask, its 98. Any way to have the motor cleared for street use, from DOT, EPA?

I did some extensive research, and the answer is "no", DOT and EPA won't allow it. If your state doesn't perform smog inspections, nobody has to know what engine you have. What they don't know, can't hurt them...

Post by **safxtacy** » Sat Jul 08, 2006 1:02 pm

ok im new to "THIS" site but im kinda lost on what exactly hazw8st does i had a few questions first do u own ur own shop and what exactly do u hve to do thres so much chemicals and other stuff lsted in different orders im lost but what exactly do u do is it a liquid or something or messing with ecu please try to make it clear and in order im not the sharpest knife in the drawer

Post by **silninty** » Sat Jul 08, 2006 2:59 pm

I have a SR20DET in AZ and have gotten a slap on the hand here when I brought it to get tested. There are two types of "cop" type people, the ones who only care about the law...(which means they know nothing about cars), and the ones who love cars so an SR20DET would normally make these guys smile. The problem that I have lies in the air recurculation system. It is illegal to take it off of any engine to drive on the street, yet if your going to "fool" your local emissions testing facility your going to need a working air recirculation system on your SR20det 240sx. To make this work, you need to create a new steel pipe no less than 18" that goes around your steering column. No prob there, now you have to block your stock hole on your downpipe, no prob there and create a new hole on the side for your modified ARS tube. It works on my car but it looks horible. I guess next car I'll take my time more, I like a car that is modified to look like it's supposed to be that way. I don't know of a single company that makes a USDM swaped SR20DET downpipe with a relocated ARS tube hole. End result the car passed emissions better than any american car I have ever seen, I never played with timing or anything else, it was stock but passed with flying colors even though it had a racing cat and 3" exhaust all the way down.

Post by **hazw8st** » Sun Jul 09, 2006 5:11 pm

Try email next time.......

Post by **Neil** » Mon Jul 17, 2006 2:47 pm

Just passed emissions today:

Stock S13 SR Blacktopo.e. SMIC w/ Koyo3" Catco catNew 300z O2Vented crank case / vc~85°+ ambient temperature

HC: 90ppm out of allowed 150CO2: .39% of .8% allowedNOx: 1734 out of 1750 allowed (no egr)

no problem with visual in spection, the motor says 'nissan' on it. if anyone asks tell them its a special edition 240.

Post by **FAST-DATSUN** » Sat Jul 29, 2006 8:10 am

what about the VISUAL part of the test and the fact that the engines (sr and RB) do not show up on the approved swap list???????//

Post by **Neil** » Sat Jul 29, 2006 2:39 pm

If they really have an "approved swap list" at your emissions center, I'll be surprised.

Don't say anything. The motor says Nissan on it, noone is likely to notice anything strange except for a couple shiny chargepipes... if they ask just tell them it was a rare 'special edition'

Post by **hazw8st** » Mon Jul 31, 2006 9:46 am

nistangclan727 wrote:would an sr pass in oh

jjh wrote:nice for locking the thread, i was wondering in nj has smog testing.

hazw8st wrote:Try again, back door smog for an SR20DET for 2 bills..... we're in 2006, these smog techs are asking $400 bucks here in SoCal.....

FAST-DATSUN wrote:what about the VISUAL part of the test and the fact that the engines (sr and RB) do not show up on the approved swap list?

Visual isn't an issue anymore, there are loopholes that bypass visual as long as the diagnostics and functional are within the emissions mandates.

Post by **Thebigjc** » Wed Aug 23, 2006 12:27 pm

What about Washington, anyone tried here yet?

Post by **Thebigjc** » Wed Aug 30, 2006 1:43 pm

Also any issues running the denatured Alch. fo a short period of time in an sr20det?

Post by **hazw8st** » Fri Sep 15, 2006 4:34 pm

Thebigjc wrote:Also any issues running the denatured Alch. fo a short period of time in an sr20det?

Running on denatured is not turnkey, you would have to tune the vehicle on denatured, then pretest it before the actual emisiions test.

Post by **domofun** » Mon Oct 09, 2006 9:57 am

hey where in so cal can i do this i need to smog mine thanks

Post by **FusionR300zx** » Sun Dec 03, 2006 10:54 pm

hmmm... how about this... chicagoo...98 (OBDII) with a OBDI redtop...?

what should i do?

Post by **Shaefer Thomas** » Tue Dec 05, 2006 5:53 pm

I have a 240 that I bought in Texas, swapped an SR into it and moved back to Michigan. Michigan has absolutely NO laws whatsoever regarding smog or anything even related to it. I want to keep the car registered in MI because I am about to go to school in Washington. Im pretty scared about all this smog BS, and I REALLY dont want to get rid of my car after all the hard work I put into it.... Anyone have any advice on Washington's smog tests? I hear you have to go to an official testing center so there is a slim chance you will find a "friendly" person there.... Just need a little insight into this.. I Know Washington has a couple 240 guys with SR swaps, cuz Ive seen them around. Any help would be greatly appreciated.

Post by **TchouikoS13** » Sun Jan 14, 2007 10:28 am

If you use propane, wouldn't your car be registered as a propane car????

Post by **180fan** » Thu Feb 08, 2007 11:11 pm

not to mention when they revert your car back to use gasoline, you get pulled over you'll still end up going to the ref anyway since the officer won't be able to verify if it's propane or not. From what I've seen, if there's any doubt, you're going to the ref.

Post by **TchouikoS13** » Tue Feb 13, 2007 8:23 pm

180fan wrote:not to mention when they revert your car back to use gasoline, you get pulled over you'll still end up going to the ref anyway since the officer won't be able to verify if it's propane or not. From what I've seen, if there's any doubt, you're going to the ref.

Kinda screwed there... Rather pay like 200 bucks for a hookup than a 400 dollar convention

Post by **Happytoys** » Fri Feb 23, 2007 11:06 am

Can anyone tell me where/how to find requierments/laws regarding swaps and smog for California? Specifically Sacramento. Also, u think it would be best/possible to keep my car titled in oregon but still be in cali

SMOG Legality - Testing, Tuning, Etc.

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