i ran cated TBE, then went catless. i prefer catless, seems boost hits alittle faster, but that could just be me. but it is alittle louder. it smells.... remember that. im running cobb stage 2. and it stinks. i went on a drive with 2 wrx's, all 3 of us running catless, i was the third car in back and omg!!! i had to roll up the windows it stunk soooo bad. so just be ready for that. aguy i know was trying to sell me a catless downpipe because "his girlfriend was sick of the smell". my girlfriend doesnt like it, but she dont care cus she says as long as it is fast and sounds good, who cares.
im not sure about smog and cat requirments in your state, but if a cop is behind you, i strongly sugjest pulling into the first gas station, or where ever to get away so he doesnt smell it. i noticed, i basically smell like an older muscle car, or older truck, just alot of unburned fuel. im hoping new plugs will help burn up that excess fuel and a nice protune i know will help.
MANIC on WRXmoders.com has a protune and catless, he said he has zero smell, thats because he is well tuned. not running rich. just thought i would through in all this jibber jabber, hope it helps