I have an 04 cts-v with an ls2, with ls3 heads, cam, and tvs 1900. would say about 600-700 fwhp, never dynod, so no clue. currently the exhaust has no cats, (no emissions here), but the car is going to my brother who lives in an emissions state. i need to add cats to the car. any recommendation on which cats to use?

 

Which state is your brother in?
You don't say if your car has headers.
Are headers allowed in your brother's state? If so any good high flow converters will do.
If not, you might have to go with a stock setup of manifolds, cats, etc.

 

Kooks sell some green cats that are for high hp and blower car situations.

 

G-Sport by GESi cats. They have EPA-compliant cats with a 400 cell count that are rated to 850 HP per cat. Part number 85230. They have another that is rated to 500HP per cat, as well. Part number 50230.

Kooks Green Cats are GESi cats.

 

it does have headers, headers are allowed as far as i know, he lives in the washington dc area.

yea i had seen g-sports and kooks, figured that was probably my best bet

 

Tell him to move out of that commie bullshit

 

Someone from there would have to chime in but from the posts I've read over the years they are almost as bad as cali in that regard.
Best thing to try is add a set of cats take it in and see if it'll fly. If not then time to start the back to stock process part at a time till it does.

 

The DC area is made up of 3 states MD, VA and DC which one?

 

i've told him multiple times

thats what im afraid of, i fear we may have to take everything off the car.

Stafford, Va to be more precise.

 

Pretty much rule for any of those commie emmission states is that if it's not as it left the factory it wont pass. of course I'm sure there are ways. But most people don't like the inconvenience and want a sticker every year to be a simple drive up pass and drive off stocks your friend in those places.
If you don't mind as it does evolve keep us updated here just for fyi and anyone else who might find themselves in the same boat.

 

With Trump's new EPA removal of regulations, I would do a good look if you need to worry about having cats or not!
Let us know what you find.
Hopes this helps.

 

Looks like the new reduced standards will effect the current laws for 2027 which were very restrictive. But not retroactive for older vehicles.
So since I am not a Lawyer because my parrents were married, I do not know what to say about your cats.

What! legal mumboljumble!
• Reconsideration of “Multi-Pollutant Emissions Standards for Model Years 2027 and Later Light-Duty and MediumDuty Vehicles” (89 FR 27842; April 18, 2024).
So, not untill 2027?The Trump administration has begun the process of rolling back greenhouse-gas emissions rules set by the Biden administration for automobiles and trucks, the Environmental Protection Agency announced Wednesday.

The agency will reconsider the proposed emissions standards for light-, medium- and heavy-duty vehicles beginning in model-year 2027, according to the announcement. The EPA is also reopening the greenhouse gas Phase 3 standard and reevaluating the Heavy-Duty Nitrous Oxide (NOx) rule, which sought to remove the most harmful pollutants emitted from diesel-powered trucks, because of “significant costs” for the industry.