Headers , Exhaust and emisions in Colorado

[4-cam]

I decided to start a new thread as I start my journey with Mods and emissions in Colorado.
I decided to go with my own version of the FBI Dynomax setup. I just finished fitting and welding it together. I installed V-band clamps just ahead of the rear mount for easy removal. I did not go with the NPP setup yet as the ones I found available were a small fortune. I am using clamps on the tips so the NPP setup will be a future mod. I also want to investigate using an electric valve and switch instead of the vacuum operated system.
In Colorado we have to keep the emissions equipment intact with the AIR system in place, Cats and pass the IM240 treadmill test. I went with Stainless Works performance connect headers and added air tubes so the stock air system should bolt right up. These are currently being coated. I should have them back next week for installation. With the purchase of the headers from the group buy last summer , I also ordered SW high flow Cats. Thru others experience on this board, I was advised that there is no way it would pass emissions with those Cats. I decided to first install a set of Universal OBDII compliant Magnaflow Cats for the initial emissions test along with the stock tune. These are 400 CPI, not 200 CPI like SW and are suppose to have more Heavy Metal in them than the std high flow universal cat. Along with Being 5" dia. vs the 4" SW. I will wrap the Cats to keep them hot and as active as possible. I'm hoping this, along with the stock tune will get me thru the initial emissions test. In Colorado, if you have an active emissions sticker when the car turns 25 years old, then you no longer need further emisions. If this works out,it will be my last emissions test, then I will install the SW cats and work on the Tune for optimum performance.

[Schrade]

Nice lookin' hardware!

Keep the snappics comin' there...

[mike100]

I did something similar, but I used oem catalysts because I think they use a lot more precious metals(platinum and palladium) in the substrate than universals. I have yet to run my car on a gas analyzer since putting the LS7 cats on the end of my long tube headers, but it passes the smell test for sure. The air injection was also retained to help light them off sooner.

[FU]

I have seen these cars (stock & tuned) pass the sniffer test W/O cats.

[Greg1960]

Sent you some info about the new laws in Colo.

[Paul Workman]

Originally Posted by Greg1960

Sent you some info about the new laws in Colo.

It has been 15 years since I lived there, but I seem to recall that emissions compliance went county by county. Jefferson = yes, Park = no (counties I lived in). Has that changed?

[Franke]

Originally Posted by Paul Workman

It has been 15 years since I lived there, but I seem to recall that emissions compliance went county by county. Jefferson = yes, Park = no (counties I lived in). Has that changed?

Yeah Paul to bring you up to date. Colorado expanded the area for emissions in the front range counties. Park is still exempt. They also changed the law last August to read that collector cars (5 year plates) are now required to be 32 years old instead of 25 and must have emissions 2 speed idle check every 5 years. They have to have been built before 1976. Collector cars were exempt from emissions before. Also, The owner must sign an affidavit stating they will not drive the car more than 4500 miles a year. Can you believe this stuff. I think people were cheating and getting collector plates to do daily driving as I have see some real junk with these plates on them. Its about the money too.
P.S. A few years ago they tightened up the standards to about almost 50% of what they were initially.

[Franke]

Good job Darby. I'm relieved to hear that so that if some day my cats fail I can go aftermarket with headers etc. I don't know Dominic but good work there too.

[4-cam]

Emissions readings: failed HC in original test
Limit for HC- 1.5 gpm
Failed test-3.6 gpm
Passed - 1.27 gpm

CO limit-20 gpm
Failed test-1.1092
Passed-1.1701

NOx limit-3.5 gpm
Failed test-2.3
Passed-2.7

Colorado has this goofy grams per mile reading. No real way to convert to ppm as a 5 gas analyzer would read.


After i put a few more miles on it today I dont think im done yet but at least emmisions is done . I can work on it and be legal.
Plugs are still looking to hot. Even with colder ngk bkr7e plugs they are grey/ white. I dont think its a tuning issue at this point. I think somthing else may be going on. When we first put the new tune in it it seemed to run great. The more I drove it , it seems go run rough, and the flywheel starts to make noise. I shut it down, reset power to the ecm and restarted it and it smoothed out and ran better. No codes were set. Then started doing it again and repeated the cycle after a out 1/2 hr of drive time. Could the ecm be pulling fuel out for some reason? From previous data logs the O2 sensors seemed ok and the curent ones only have about 2k miles on them.
Anyone have any ideas? I didnt get any data logs during my last run, so I need to put a few more miles on it and do so.

[XfireZ51]

Actually grey is not a problem. It has to do w the ethanol,and additives in the gas. If ur expecting light tan, that's not necessarily the case any longer. To truly judge u should do a "plug cut" removing the threaded portion of the plug and looking at color. My plugs are not tan.