Planning legal exhaust

[dthree]

So I'm trying to plan my upgrade so I don't waste money. I have a perhaps misguided interest in keeping the exhaust legal, so that means a EPA-approved cat. (Yes I am aware that removing a working cat is also illegal, but I am ok with my own hypocrisy.) I have found that the only aftermarket cats available that are specified for the AWD are either 2.25" or 2.5" and only Random Tech has the larger one. So, my idea is to eventually use a 2.5" downpipe, a 2.5" Random cat, and a 3" catback. I would think I need a custom flange made for the catback, because they either have 3" flanges for matching DPs or 2.25" adaptors for the stock cat. Other than that, where could I find a 2.5" DP that would bolt to the 2.5" Random cat? The eventual upgrade plan is a EvoIII 16g. What would I need for a DP to be compatible with this turbo later but work with stock turbo now?

 

[hypnoticpimp]

check out the Road race downpipes

Eclipse Exhaust System Upgrades

 

[crimsondragon]

Some of our vendors do sell 3 inch high flow cats. I plan on getting one, welding on some 2 bolt exhaust flanges and putting it on for inspection. Yu don't have to stick with a 2.5 inch dp.

 

[dthree]

check out the Road race downpipes

Eclipse Exhaust System Upgrades

Thanks, I'll look at them.

Some of our vendors do sell 3 inch high flow cats. I plan on getting one, welding on some 2 bolt exhaust flanges and putting it on for inspection. Yu don't have to stick with a 2.5 inch dp.

If I'm reading the info right, for a cat to be street-legal it has to be EPA-approved for each particular car. I've searched through the forums and found a number of posters discussing how they had failed emissions (even in non-CA states) for running cat that was not approved for their car. This was done, I assume, by running some ID number off the cat through a database. For example, Magnaflow has a 3" cat for Evo 9s, but that same cat would not be legal on a 98 eclipse GSX despite having the same engine. I suppose all this only matters if your state inspection shop runs the number, many just do a visual check from what I hear. I guess I am just paranoid that I'll fail inspection despite having a good sniff test and have to put the stock exhaust on just to pass.