Here in TX we have a two speed dyno test (25 and 15). Here are my results: 25 mph - Standard - Current Reading - Result HC(PPM) - 144 - 143 - PASS CO(%) - .92 - .91 - PASS CO2(%) - 13.5 (not judged) O2(%) - 1.5 (not judged) NOx(ppm) - 1014 - 1908 - FAIL DILUTION - >6 - 14.4 15 mph - Standard - Current Reading - Result HC(PPM) - 148 - 153 - FAIL CO(%) - .83 - .94 - FAIL CO2(%) - 13.4 (not judged) O2(%) - 1.6 (not judged) NOx(ppm) - 1110 - 1922 - FAIL DILUTION - >6 - 14.3 My setup is a 2001 LS1 (LS6 intake) w/4L60e with a custom exhaust that has a non-AIR high-flow CAT. So...huge NOx was the main culprit. I had ARD put on a "high-flow" cat back when I had the exhaust done, but I'm not saying that's not the problem. Could they have used a crappy CAT (maybe too small)? I don't have AIR lines - so I ran the car for 15 minutes before waiting (idling) at the inspection place for about 15 minutes. Temp looked to be up there. I looked for vacuum leaks and wasn't able to find any using some carb cleaner. When I created a vacuum leak, the car definitely idled higher - so I don't think I've got a large vacuum leak - as I wouldn't have seen a big difference there. I'm going to remove any added vacuum lines today and see if it affects anything. Any other ideas? Could old gas cause this big of a problem (2 months)? Thanks for any and all help. I'm really close to calling it quits.

Idling doesn't keep the cat warm.

Have you modified the 2001 set-up at all? Different injectors, cam, tune?

Are you being tested to 1987 or 2001 standards?

Remember LS1's had a cat on each bank and a cat after the y-pipe.

The 2001 setup is stock as far as I know. The dyno numbers point to that as well. The tune is a stock 2002 with enough changes to make it work without AIR and rear 02s. It was tested to 1987 standards. Wow...cat on each bank and another after the Y? Didn't know that. I'm thinking I definitely need a full-fledged cat on this car.

I'm almost positive that my friend's stock 00 z28 had 2 cats total. One on each bank. There wasn't ever a 3rd cat anywhere, even on the lt1 cars.

My '02 had just two, the pup cats on each side. Passed emissions just fine (almost zero across the board) with the AIR system removed. Did you drive it around for 20-30 minutes before you took it to get smogged? It could also be that the cat isn't close enough to the heads to stay hot enough.

When I lived in an emissions county & had to be tested, I'd drive to a shop 20 min away to get the cat hot, not just around the corner from me.

Idling doesn't get the cat hot enough. Driving does.

Also check what the hc and other levels are for your car. They could be way lower than a stock ls car is alowed. I had this problem with my lt1 swap a few years ago.(the car doesn't require emissions any more thank God) The stock lt1 camaro is alowed 2.0 hydrocarbons and an 88 Iroc is alowed .9 hydrocarbons. I think that the politions are trying to get old cars off the road by making emission standards tighter. good luck I hope you are not in for the nightmare I had. It took me 10 trys to pass the im240 test.
Kory

the ls1 cars had two cats on them. one on each bank. also you are not using the rear 02 sensors which are the ones that check the temp of the cats and make adjustments. you prolly had someone turn a few settings around on it. they will have to set it up to run lean and then you will have to go back and redo it.

Are there any ways around getting the test done in Texas? Here in Missouri, '95 and older don't get emissions tested, only safety. But for the cars that DO get tested, you can get a waiver exempting from the test with annual mileage limits and I think you can't drive the car in certain areas. Also, here I believe you can register a P.O. Box in a non-emissions county and get around it that way as well.

Well - I have some suspicions. Bought a non-contact temp gun today. I took the car out for a hard drive (20 minutes of 0-90 back and forth, 2500+rpm cruising) and then parked and tested the inlet/outlet temps on the cat. I was seeing around 100 degree increase from inlet to outlet - which is consistent with a cat doing its job (http://www.randomtechnology.com/technical.html is great). So...what could it be? It could be that the shop put on a 2-stage cat instead of a 3-stage one. The third stage is...NOx.

Having fun with the car, I ran 1/3 pt seafoam through a vacuum line on the tb (per instructions), waited 5 minutes, and then ran the car for a while. It took me getting it up to 2500 rpm for it to start making any white smoke, and even then was minimal compared to other cars I've seen. I'm thinking carbon buildup isn't an issue.

Lastly, I took the car out for what a typical ride would be - slow starts, cruising ~2200 rpm, only 1 0-70 foot-flooring funtime. Brought the car in at in-city speeds (30 mph or less), and retested the inlet/outlet temps of the cat.... I'm now seeing a temperature DROP. The CAT's not functioning after what would be a normal drive...there's no way I can run&gun it all around town until the inspector is ready.

So - we've narrowed a large part (maybe the only part) of the problem down to the cat not doing its job. Potentially, the cat may be a 2-stage and not be doing anything for NOx. I'm thinking the cat not heating up is its placement:


That far back...it's just not heating up enough, is it? This pic was from the installer...and I can't quite make out the markings on the cat to cross-ref it either. So now I'm trying to figure out how to re-do my mega-expensive exhaust to incorporate 1 or 2 good 3-stage cats closer to the manifolds.

Any thoughts, suggestions, comments? Anybody running an auto w/manifolds and have a great exhaust setup? I'm about to chunk my nice stainless $$$ setup that ARD built (I've had to redo or have them redo so much of their crap it makes me sick).

Time to dig through the archives for exhaust pics. Post 'em if ya got suggestions.

Your issue is the cat being nowhere near where it should be. Get that thing as close to the engine as possible.

I would not worry about the type so much as its' placement. Spending a ton of money on uber high flow blah blah cats will not help you with your dilema.

By the looks of it, you should be able to squeeze 2 pup cats up close to the manifolds. I picked up a set of small SLP cats on ebay for ~$120, which is what I plan on using.

converter needs to be closer to the manifolds...

So - by "pup cats" - would that be say...smaller 4-cylinder intended 3-stage cats? Here's the new placement I'm thinking could work:


A cat like this one at Summit?

Here in TX, after a car is 24 years old, visual inspection only, no more emissions testing, so it's a rolling year thing.

You can get a waiver IF you fail & repair, fail & repair....After a certain $$$ amount, they decide you've spent enough at least TRYING to get it fixed. Dunno if the waiver is good only for that year, if you set new standards for you to meet, or what happens the following years.

And P.O. Boxes aren't allowed for Registration in Texas. Must have a physical address, even if you do not recieve mail at that address. Most of my little town has converted to P.O. boxes except in outlying areas, but I'm on one of the few streets IN TOWN that still have mail boxes.

I was thinking some thing like http://cgi.ebay.com/ebaymotors/Haman...item19b26dd0a5

Just kidding.. More these: http://cgi.ebay.com/ebaymotors/PYPES...item5636f7e823

No wonder you aren't passing... that cat is way back there. Those Summit cats are a little longer than the original GM LS1 pup cats (which come directly off the manifolds). Your diagram looks like it'd work. The closer, the better.

Got two MagnaFlow 94106 on order and some extra stainless pipe to fill in the the old cat location.

HA!

Actually those second set look kindof nice...

Honestly you probably need a more complete tune. Mine was tuned at ARD as well, and it won't pass emissions, even with two cats. I do have a Comp XER281HR cam though....at idle it has an HC count of about 590ppm. However if you pull the MAF/O2 fuse it leans it out to about 150 LOL

Im just answering to the 1st post, finding it kinda odd yours failed.

I passed Ontario '97 standards with:

6.0L LQ4
Stg. 1 LS6 cnc heads
222/224 on 112 cam
FAST intake
underdrive
Pacesetter race headers
Y with magnaflow 55959 bullet cat's

passed easy.

ASM Test
HC ppm - 18 - 242max
CO% - 0.03 - 1.92max
NO ppm - 169 - 2520max

Idle:
HC ppm - 195 - 300max
CO% - 0.09 - 1.50 max

Edit: on a further note, my ASM is a 40km/h (approx 25mph) test. My idle A/F reading is 13.6, and my 40mph A/F reading was approx 15.0. Its not a finished tune, as the PE tables arent done, but it passed there.

Seeing what my results were there, ive got kinda testy, and ive got a 232/234 112LSA cam im going to put in it. I think if i absolutly dial my tune, ill be able to get it to pass e-test also.

I hope Ontario emissions are easy on me too Sheldon

I'm surprised you still have to get tested to 87 standards.... Thought motor swap would mean you have to acheive those standards for that motor. OBDII system check not OBDI 2 speed test?

To get my parking brake working, I had them adjust the idle down. After 4 months of frustration with a non-working parking brake - I bought EFI Live and fixed my idle tables (parking brake works now!). Since my engine is dead stock, I copied a stock '02 auto tune down onto the ecm leaving just the parts out so it will run without VATS, rear 02s, etc. So I think my tune should be alright.

That would be nice - but OBDII system check would reveal my lack of AIR pump and rear 02s I believe.

Woah. Maybe the guy tested me against wrong standards? I couldn't imagine the target numbers being that different....even if you are in Canada. I would have passed easy with a 2520 max ppm NOx. Crazy!

I wonder if I can look up my target #s somewhere on the internet...

According to http://www.txdps.state.tx.us/vi/publ...l/chapter4.htm :
Light Duty Gasoline Powered Vehicles Less than 8,501 GVW Preconditioned Test Model Year CO (%) HC (ppm)
1982 and newer 1.2 220
Heavy Duty Gasoline Powered Vehicles 8,501 or More GVW Preconditioned Test
Model Year CO (%) HC (ppm)
1982 thru 1984 5.0 500
1985 and newer 3.0 300



So...either heavy or light I would have passed. It doesn't mention NOx at all...

im still going to go with the cat being way to far back. ther ones for the fbodies with the ls1's are right near the manifolds. you are going to have to either mount a bigger one closer or two little ones.

Oh I definitely agree. Both cats arrived today and I'll be having them put on Monday according to the diagram I posted. Hopefully the target #s are right, else new cats in better places may not help much.

Got the new cats put on by the best exhaust shop around - FMG Exhaust in Crosby, TX ( gotta put a plug because they're awesome ). For the time being we left the 3rd non-working cat attached thinking that the two forward cats would heat up enough to lite it off as well. I'm not sure if that's what occurred, but my new readings are really low.

25 mph - Standard - Current Reading - Result

* HC(PPM) - 144 - 8 - PASS
* CO(%) - .92 - 0.02 - PASS
* CO2(%) - 15.1 (not judged)
* O2(%) - 0.7 (not judged)
* NOx(ppm) - 1014 - 501 - PASS
* DILUTION - >6 - 15.1

15 mph - Standard - Current Reading - Result

* HC(PPM) - 148 - 10 - PASS
* CO(%) - .83 - 0.03 - PASS
* CO2(%) - 15.1 (not judged)
* O2(%) - 0.7 (not judged)
* NOx(ppm) - 1110 - 535 - PASS
* DILUTION - >6 - 15.1

Gotta smile at those numbers

Went back and got the third cat removed thinking that it was causing an issue with backpressure (and the front 2 cats were doing the smog job just fine). Removing it made the exhaust louder, but didn't solve my issue - what seemed like transmission slipping. Turns out my new-to-me tranny is still taking in fluid, as I've checked it 2 more times now and added. I believe the lokar tranny dipstick hacked together by ARD is incorrect in its reading - so that replacement will have to wait until there are more funds.

But hurrah - car passed emissions (totally legal too!), and is now registered, tagged, and titled here in the great state of Texas.

That's what I thought, too. When I swapped in the '86 LG4 into my '82, I put the '86 underhood stickers in (well, used the '86 hood, which had the stickers on it). When I arrived at the test station, they scanned the VIN, which of course comes up as an '82 V6. It passed every time, but after the last time I went to the Colorado emissions website and discovered the size of the engine doesn't matter, they're all tested to the same standards. But, the requirements got stiffer for the 1986 model year, so if they had tested it as an '86, I would have failed one of the times it was tested (the tech that ran that test was an idiot; letting the speed fall too far, gunning the engine to catch up, overshooting and letting the throttle off completely; did that over and over - that kind of stuff makes emissions readings skyrocket).

Anyway, congrats, Candy. It really did sound like a cat issue.

Air care colorado really seems to have strict hiring standards and training

In the last 15 years, I've had a lot of cars there. I've only had a real issue with the employee twice - the one I just described (which didn't result in a failed test); and one time when the vehicle did fail, the supervisor came over and lit into the guy, pulled the car back around and did the whole thing over again, and it passed - apparently the guy who ran it the first time hadn't completed his training and wasn't qualified to run it on the dyno.

glad to hear you got it sorted out

so glad I don't have to worry about that stuff here (yet)

-jason

Wow.....My 87 L98 at 190,000 miles, was every bit as clean as your modern tech LS1, at my last test. I no longer live in am emissions county, so no more testing for me.

My counties tests were a little different than yours, but the results are very close, despite the high mileage! And I didn't even have a smog pump on, or thee A.I.R. injection tube to the cat. In fact, my cat is "technically" illegal, because it isn't the right kind.

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Mar 15, 2007, 02:56 PM

High Speed-2692rpm
HC 220-limit...............4-my reading
CO% 1.20-limit.............0-my reading

Idle
HC 220-limit..............16-my reading
CO% 1.20-limit.........0.01-my readin