NEVADA SMOG DIABLO TUNE LONG HEADERS QUESTION - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

SilverState · 02-24-2014, 12:45 PM

I have been getting an inefficient catalyst code when pre-testing smog in Nevada with my Stainless Works long tube headers with 3" hiflo cats on a '10 L99. The people at Diablo say they can adjust my tune so the light on my dash won't come on, but I am wondering if that will solve the Nevada computer smog issue. I don't want the smog machine to show that a sensor has been turned off or something similar, because I think that will cause the car to fail smog. Anyone in Nevada know whether tuning out the inefficient cat issue will still cause the car to fail smog? I am not worried about the visual inspection.

granatl · 02-25-2014, 12:09 PM

Nevada allows one of the emissions flags to not be set. What the Diablo people are doing is likely disabling that particular test which does stop the CEL light (they have a choice to either just not trigger the light, or set it so it's not an error, period).

Once you get the computer re-flashed, remember that you have to drive the car ~60-65 MPH gently until the fuel trims set and the various emissions flags set (let's say more than 100 MPH, but it just depends on various things).

SilverState · 02-25-2014, 03:15 PM

thx!

SWAT · 02-25-2014, 03:32 PM

Not to hijack this thread, but I have a couple of questions regarding the smog test for Nevada. Currently we live in Michigan & there is no test. I can do whatever I want to my car & still drive it on the streets. We are seriously considering moving to Vegas in a couple years. I don't want to remove a bunch of stuff just to pass the smog test.

Right now I only have a cat back but will probably be adding a few bolt ons or maybe more, depending.....

Are all long tubes a no no? How about stock manifolds (or possibly) shorties with Solo cats? Any smaller cams out there pass emissions, or would it not even be worth it? I would probably not be doing any head work or SC. Of course it would have some sort of CAI.

Just curios of basically what you can get away with in Vegas & still drive on the street. I don't want to remove anything for the emissions test & then put it back on.

Thx

Vroom_vroom · 02-25-2014, 03:55 PM

On all the new stuff they just plug in to your obd2 and make sure the computer has no emissions codes and check to make sure there is no smoking, but if your the guy that has no cars and other goodies just go to a certain part of town and give the guy a hundo and you suddenly pass smog!

RRW · 02-27-2014, 06:47 PM

One of the issues with the stainless works headers and high flow's is the placement of the 02 it's caused issues before with the monitors tripping up and causing it to fire off a cat efficiency code. As for Nevada as a whole you can get away with no cats if it's calibrated properly and you pick the right smog places to head to. If you go to one of the "shop" style smog places that insist you come in for a full check up.. found that when I first moved here you will most certainly fail. I know several guys in town who have had issues with that. I however have never had cats and will be removing the ones from my 12' car here very soon installing long tubes and NOT putting cats back on. There is really not an issue again it's really dependent on the calibration. I know that with diablosport there are a few things that are not as flexible with the monitors as there are with the other ways to edit the software. I know for a fact because I use both diablo and HPT.

Best of luck to you. Hope my info helped

vegassam66 · 03-19-2014, 10:05 PM

I recently smogged my 2012 superchanged 2/SS with no cats with no problems at the dealership. Garth at Leading Edge Performance did all the work and custoim tune. I was a little worried about getting it smogged, first one since supercharging, Garth hooked the computer up and double checked if any issues. Car passed with no problems.

axis · 03-20-2014, 12:09 AM

It's all in the tune. Plugging into the OBDII port will check to see if any checks are on going or have been tripped. A PROPER tune will turn off all the tests for the cats, thus eliminating any open or failed tests. If they have a actual sniffer, you'll most likely fail that one. Good thing is, most states don't use those.

02-24-2014, 12:45 PM	#1
SilverState Drives: 2010 Camaro SS Join Date: Feb 2010 Location: United States Posts: 23	NEVADA SMOG DIABLO TUNE LONG HEADERS QUESTION I have been getting an inefficient catalyst code when pre-testing smog in Nevada with my Stainless Works long tube headers with 3" hiflo cats on a '10 L99. The people at Diablo say they can adjust my tune so the light on my dash won't come on, but I am wondering if that will solve the Nevada computer smog issue. I don't want the smog machine to show that a sensor has been turned off or something similar, because I think that will cause the car to fail smog. Anyone in Nevada know whether tuning out the inefficient cat issue will still cause the car to fail smog? I am not worried about the visual inspection. __________________

02-25-2014, 12:09 PM	#2
granatl Drives: 2SS RS ABM A6 Join Date: Jun 2010 Location: Pahrump, NV Posts: 273	Nevada allows one of the emissions flags to not be set. What the Diablo people are doing is likely disabling that particular test which does stop the CEL light (they have a choice to either just not trigger the light, or set it so it's not an error, period). Once you get the computer re-flashed, remember that you have to drive the car ~60-65 MPH gently until the fuel trims set and the various emissions flags set (let's say more than 100 MPH, but it just depends on various things). __________________ Jack Bilger

02-25-2014, 03:15 PM	#3
SilverState Drives: 2010 Camaro SS Join Date: Feb 2010 Location: United States Posts: 23	thx! __________________

02-25-2014, 03:55 PM	#5
Vroom_vroom The gritos pollo!!! Drives: Like a idiot Join Date: Jul 2012 Location: Las Vegas Posts: 1,215 View My Garage	On all the new stuff they just plug in to your obd2 and make sure the computer has no emissions codes and check to make sure there is no smoking, but if your the guy that has no cars and other goodies just go to a certain part of town and give the guy a hundo and you suddenly pass smog! __________________ ______ If you don't stop how can they give you a ticket?-The Big Tuna___ '12 1Ls Camaro; Slp loud mouth I\|maganflow x-pipe\|Injen long ram intake\|brembo brake upgrade\| russell s.s. lines\|2LT polished 19's\|billet 5mm spacers\|tinted tail lights&markers\|pdmi\|billet c. can\| '13 Avenger R/T '77 T/A 6.6;, draining my wallet.

03-20-2014, 12:09 AM	#8
axis Search Ninja Drives: 2010 Black 2SS/RS A6 Join Date: Oct 2009 Location: Central Ark Posts: 7,183	It's all in the tune. Plugging into the OBDII port will check to see if any checks are on going or have been tripped. A PROPER tune will turn off all the tests for the cats, thus eliminating any open or failed tests. If they have a actual sniffer, you'll most likely fail that one. Good thing is, most states don't use those. __________________ 2010 Black 2SS/RS A6 Halltech CF 102 fed GPI modded intake manifold Bo (knows) White ported TB Kooks LT's/ Dynomax VT Pfadted (springs/sways) Dyno tuned by Rhino and GPI I once parallel parked a train.

02-25-2014, 03:32 PM	#4
SWAT Drives: 2011 2SS RS L99 Join Date: Jan 2011 Location: Grand Rapids, MI Posts: 5,708	Not to hijack this thread, but I have a couple of questions regarding the smog test for Nevada. Currently we live in Michigan & there is no test. I can do whatever I want to my car & still drive it on the streets. We are seriously considering moving to Vegas in a couple years. I don't want to remove a bunch of stuff just to pass the smog test. Right now I only have a cat back but will probably be adding a few bolt ons or maybe more, depending..... Are all long tubes a no no? How about stock manifolds (or possibly) shorties with Solo cats? Any smaller cams out there pass emissions, or would it not even be worth it? I would probably not be doing any head work or SC. Of course it would have some sort of CAI. Just curios of basically what you can get away with in Vegas & still drive on the street. I don't want to remove anything for the emissions test & then put it back on. Thx

02-27-2014, 06:47 PM	#6
RRW Drives: 2012 ZL1 Join Date: Feb 2014 Location: United States Posts: 11	One of the issues with the stainless works headers and high flow's is the placement of the 02 it's caused issues before with the monitors tripping up and causing it to fire off a cat efficiency code. As for Nevada as a whole you can get away with no cats if it's calibrated properly and you pick the right smog places to head to. If you go to one of the "shop" style smog places that insist you come in for a full check up.. found that when I first moved here you will most certainly fail. I know several guys in town who have had issues with that. I however have never had cats and will be removing the ones from my 12' car here very soon installing long tubes and NOT putting cats back on. There is really not an issue again it's really dependent on the calibration. I know that with diablosport there are a few things that are not as flexible with the monitors as there are with the other ways to edit the software. I know for a fact because I use both diablo and HPT. Best of luck to you. Hope my info helped

03-19-2014, 10:05 PM	#7
vegassam66 Drives: 2012 Camaro 2SS / RS Join Date: Feb 2013 Location: Las Vegas Posts: 99	I recently smogged my 2012 superchanged 2/SS with no cats with no problems at the dealership. Garth at Leading Edge Performance did all the work and custoim tune. I was a little worried about getting it smogged, first one since supercharging, Garth hooked the computer up and double checked if any issues. Car passed with no problems.