Technical question about aftermarket cat install

[neilbey]

2005 OBXT here.

 

I'm going to be installing a catless invidia downpipe to compliment my K&N short Ram intake, catless UP, bnr 16g turbo, and stage 2 opensource tune (cryotune - good peeps, and very patient) - obviously, I will be getting yet another tune after the extra upgrades.

 

I've got a 2.5" thunderbolt cat, and whilst my state doesn't do sniffer tests (just visual and OBD2), I'd still like to have a catalytic converter (personal reasons, I like the environment).

 

I'd like to avoid cutting into my shiny new catless DP as much as possible. Is there a disadvantage to welding one in further down the line that the stock location for the rear converter (housed in the stock downpipe). The position would be as close to the rear of the downpipe as possible, but maybe after the stock resonator). I know these things need a minimum temperature to actually work, (800 degrees Celsius IIRC), so would wrapping the spliced cat be advisable to help maintain a proper temperature? I'm sure the exhaust will be cooled by the resonating chamber quite drastically. I may just take a temperature reading at the proposed location to check if the temperatures would be conducive to a cat converters function.

 

My thinking was to have my O2 sensor CEL either "disappeared" (with some tuning magic), or the mechanical fix (taking the rear o2 sensor out of the exhaust flow enough to not throw a CEL)

 

Any input would be appreciated. TY

[neilbey]

So I see that the catted COBB downpipe for the 05-09 OBXT/LGT has the cat at the end of the downpipe as it meets mid pipe. I figure if I were to wrap the downpipe, it'd keep those gases a bit more warmer, and having a cat immediately after the downpipe couldn't be too much different.