just playin arond with this idea. i have emmisions in cali so i need shorties, but i was wondering if it would be worth it to try and fab a system up to the stock cats. anyone done this?

 

Don't waste time with stock cats. From what I have seen people say, high flow cats are definately a lower restriction. Shorties suck, but cali's lawas suck. You could do it. If you want the sound of duals you could, but would you even pass a visual with dumps?

You could always run shorties, catted Y-pipe and a catback if you had to.

 

ya i think i do have to... i hate cali. what can i do!!!! i want power!!!!!

 

I hear ya there I don't want to go with shorties but oh well I don't really know anyone to help me out too I don't want complete restriction so I want to lose the stock cat for a better flowin one, but I think I am going to go with gmmg for the catback. but then again Duals are still an option. good luck to you but definitely lose the stock cat.

 

can i loose tha cat? i thought high flows were illigal

 

High flow cats should be perfectly legal. Well....technically there are VERY specific rules about replacing cats but really all you need (even in cali) is functioning cats at the stock location with no cutouts and exhaust that does not exit under the passenger compartment.

 

It all depends on where you get your car smogged. If you get sent to the referee, technically anything non-stock is illegal. Not only do they have to be in the stock location, but they have to be the GM cats. You are allowed to replace them if you have >100,000 miles or have a malfunction, but they still have to be GM cats in the stock location. If you have stock exhaust manifolds or shorties, high flow cats are probably only good for ~2 hp anyway. The stock cats are high flow cats. I know....isn't cali cool.

 

I'm pretty sure they don't have to be GM cats.
What I remember reading (for federal emissions purposes) is that the car has to be X number of years old and/or 50,000 miles, or have a damaged or malfunctioning cat with proof of damage/malfuntion in the form of a signed statement by a professional.
The reason for the 50,000 mile/ X year thing (I think it was five years???) is that auto makers are required to warranty emissions products for that length.

 

You may be right on 50,000 or 5 years, I can't remember for sure. I have asked the smog guys about the cats though, and they can't be aftermarket cats, they have to be stockers. You will also notice that none of the high flow catted y-pipes are 50 state smog legal. I think on the OBD I cars in california, you can use an aftermarket high flow cat.

 

well you can get the JBA shorties that hook to the stock cats. then get the bassani tru-duals that bolt to the stock cats. vinci did that on a convertible here in orlando.

 

High flow catted Y-pipes for what headers? Shorties, or mid/longtubes?

 

No y-pipe with high flow cats for any setup, LT's/mids/shorties is technically legal here in california.


I have talked to a smog tech, and also asked muffler shops. Some of the muffler shops here in california sell the 50 state legal magnaflow cats, but only for OBD I. They said they could not put them on my car or they could be fined $20,000. Believe me I've checked, if it was legal I would have them on my car.