ajsfirehawk

iTrader: (4)

I purchased EFI Live Tune. Reloaded the factory tune, recall that I just put new O2 sensors and fresh TR6 spark plugs gapped at .055, went back to the emissions test and failed miserably. Numbers just a slight amount worse than my first pass prior to doing anything whatsoever. I called the Colorado Emissions tech and he is telling me zero doubt the issue is the performance Cats. "The are high flow, they do not 'light up' like OEM Cats. OEM Cats achieve full function and efficiency within 20 seconds with the substrate design and backup pressure. You will have to swap your Cats".
The one run where I was so very close to passing, the guys running the equipment made three separate passes which ties out with the State Tech's statement "The cats finally light up which is why your second run was greatly improved". This is now starting to look like a $1500 bill for a second set of cats and y-pipe to accomodate the different size of the OEM style cats. Thoughts please

WeathermanShawn

iTrader: (1)

Sounds like a lot of misinformation.

Like I said, I passed two years ago when I lived in the emissions testing zone. That was with a 220/220 114 cam. My headers are the Dynatech SuperMaxx headers with 'High-Flow Cats'. As I recall they are the "Randam Tech" variety.

The entire exhaust system was ~ $1300.00, but I believe the cats are ~$300.00.

It does not sound like your tune. If you definitely have the factory closed-loop tune in, then then your cats must really be bad. You are one of the few I know who have failed on the stock cam. Are you 100% sure your cam is stock?

Normally, Colorado has a dollar limit on repairs necessary to re-pass emissions, but perhaps aftermarket cats converters are exempted. Like I said I can only tell you my experience. I passed with an aftermarket cam, long-tube headers, and an EFILive tune.

You can always look into registering it at another location. Do you have family or property outside of the testing zone? Just a few thoughts.

Good luck..

joecar

Was engine thoroughly warmed up and hot...?

Can you post the amounts of each gas...

ajsfirehawk

iTrader: (4)

Yes, quite certain the factory tune is back in the car. The first and third tests are essentially the same results: HC 2.8085; CO 20.6962; NOx 3.6348. Whne they did multiple pulls in the 2nd test HC .71; CO 4.67; and NOx 1.579. And no, totally hit or miss on the car being hot, hot. There is normally a line, I've made 15 passes by the A.C.C bldg trying to get in when there isn't a line, a two car wait is the best I've been able to do. Early, late, mid morning...doesn't seem to matter.
Sorry for the delay, spent the last two days moving my son back home from college for the summer.

VIPRETR2

iTrader: (63)

I skimmed the thread and didn't see if you tried this option. Grab a can of "Guaranteed to Pass" type fuel additive for emissions. I know it sounds stupid but it worked for a friend of mine with a TT300ZX recently. At this point you have nothing to lose and it's only a couple of bucks. Good luck,

Larry

ajsfirehawk

iTrader: (4)

I've got the stock tune, stock exhaust back on the Trans Am in an effort to pass emissions. Any issues with leaving the Bosch 13111 O2 sensors in the sensor 1 position? Meaning up close in the factory cast iron manifold on the driver's side and just barely downstream from the factory cast manifold ahead of the cat on the passengers side.

ajsfirehawk

iTrader: (4)

A bit more information, these are the Corvette rear O2's versus the stock Trans Am front O2s

joecar

They should be ok, as long as the scantool shows them switching sufficiently (i.e. 3 or more times per second, from below 300 mV to above 600 mV and back.

ajsfirehawk

iTrader: (4)

Thanks Joecar. The exhaust is back to 100% stock manifolds, cats, y-pipe and all the way back to the axle. I truly hope all this brain damage results in passing emissions.

ajsfirehawk

iTrader: (4)

Closing the loop. 16 hours over four evenings (I work slow and carefully) I deinstalled the headers and 3 inch SS exhaust. Reinstalled the factory exhaust manifolds, cats, rear O2 sensors, y-pipe, and connected that to the Borla muffler. It passed emissions easily today after 4 failures. In fact for the HC, CO, and NOx it reduced them by 95% to 98% each. Shocking and frankly leaving me with a bit of a morale dillema. Never in my wildest dreams did I think they would make that dramatic a difference. The DMV Emissions Program inspector's words are ringing in my ears, and I'm parpaphrasing. "You will never pass emissions with a so called performance cat. They flow too freely by design, they don't build the back pressure and heat needed to light the catalyst. Stock cats light to 100% of function in less than 60 seconds"
The stock tune was actually a whisker worse on all three gases when I retested after only changing the PCM tune. We have completely Californicated Colorado. That much is clear. Words to the wise if they head down the path I did with the best of intentions, I paid extra for QTP headers with air pipe bungs in them, paid extra for performance cats, all with the intention of being a good citizen while being a hot rodder. No good deed goes unpunished.

WeathermanShawn

iTrader: (1)

You never know. Like I said, I passed with flying colors with an aftermarket cam and long-tube headers with cats. In fact the gas analysis was cleaner than my second car..a 98 Dodge Intrepid.

But, I agree it is getting tough.

Good luck in the future. You went to a lot more trouble than I did, but you are now 'legal'.

Enjoy your ride..