• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

ATT with a kitty named Soot Trap. ATT emissions passed!

WarWagon

Well it hits on 7 of 8...
Messages
10,947
Reaction score
9,185
Location
AZ
Clearly the factory size converter with the outdated ceramic innards will not work with a large turbo. It is simply too small and restrictive. This has been proven – ATT will not spool with a factory kitty. Emissions attempting to do this cause vehicles in other testing bays to ALSO fail from the smoke cloud.

This leaves me with a problem to solve as the engine is already built with the ATT and emissions are due. The OEM kitty ate too much antifreeze and oil and died from this contamination. Roto rooter did not help as the 3” banks exhaust had to go away when the 4” exhaust arrived. With the rear heater hoses there isn’t a good place to mount a gutless 3” kitty. Not sure that factory is as far back as mine is/was.

So in the junkyard of mine I came across a 4” kitty that fell off a 2008 Duramax. Kitty is larger in diameter but has more or less 4” in and out. The flanges were replaced with welds so the falling off problem with our rough roads will not happen again.

This 2008 design has spun metal vs. the ceramic substrate design. This translates into less restriction as the metal is thinner than the thick walled ceramic design. It can also take higher temperatures without melting. In fact raw diesel vapor is fed to it to burn the soot out of the DPF. It also means more room between the elements for soot to blow through rather than plug it up.

So we have a modern 4” ‘spun metal’ kitty on a 4” exhaust. A special tune was used and emissions passed. (Snap test.) :thumbsup:

Here is the good news! The regular tune runs just fine with this 4” kitty in place. So an A Team Turbo is running emissions legal with no effect on performance as far as I can tell. Of course I am limited by my precups and am only using 17PSI of boost max.

I suggest that the 4” performance converter that is spun metal would also work well. Duramax exhaust parts should be common as some owners regularly have trouble with them falling off. So testing one of these 4” kittys with 6.5 turbo, diamond, precups at higher boost would be in order. Even limited to 17 PSI of boost is a victory for a better turbo!

Some places like CA do not allow used converters to be installed and have to have an EO number for an new aftermarket converter used. Good luck getting the Magnaflow 4” spun metal converter through CARB or being in compliance if it is. I’ve not looked it up. :skep:
 
I will be installing my gutted, 4" modified soot kitty over the Xmas holiddays and taking the '99 in for CA smog. Kitty was already gutted but stock 3" connections and the '99 passed the last time with an ATT and Heath tune. Just would not recommend smogging it at 6750' elevation as it would blow a cloud on the snap test.:hihi:

1321825999.jpg
 
Just would not recommend smogging it at 6750' elevation as it would blow a cloud on the snap test.:hihi:
I was shocked at the amount of black smoke I put out with my truck at 8500 ft plus or minus in Colorado a couple of months ago.
 
I was shocked at the amount of black smoke I put out with my truck at 8500 ft plus or minus in Colorado a couple of months ago.


This is why I love EFILIVE. I've only been up to about 6,000 feet, but it smoked less up there than it does at sea level.
 
My tune was tweaked for elevation and the limits of my precups. Yes a fuel limited tune helps emissions.
 
As said above I used a 4" kitty off a 2008 Duramax. I assumed it was spun metal due to it's shape and seeing raw diesel vapor to burn off the DPF in it's intended use. I can not find any source to back this up and older Duramax converters appear to be old school ceramic from recent posts. So the composition of the 2008 kitty is in question.

Also, the first emissions test with the small OEM kitty had fuel system issues of bugs in the fuel and restricted tank sock adding to the smoke cloud.

Regardless, the ATT and kitty are still getting along even on B99. I will say it does make the exhaust smell better than the harsh smell of the 1993. B99 and #2 both have different smells... So my 1995 smells like a Duramax... My 1993 smells better than a Duramax in DPF regen.
 
Back
Top