Okay ive got a 2000 impreza L, i purchased a complete exhaust for it awhile ago, I got the Borla Hush cat-back along with Headers by Borla as well. TOday i went to go ahead and install them, i realized my cat was a POS, rusted and will not pass inspection. So i need to replace that, the hush system was designed for a WRX motor not a 2.2L non turbo. The piping is all 2.5" along with the headers, my problem is that the flanges that came with the header are meant to go from a 3" Cat to the 2.5" plumbing of the rest of the exhaust. What would the best thing for me to do to get this all set and done so i can install it?

A: get a stock cat at Mineke and have them weld the Cat-Back portion directly to the cat, then have them finish off with welding the header directly as well?

B: Buy a universal cat, cut off the edges and use the flanges that came with the system, which would require me cutting and welding anyways?

C: Other options???

1. The headers you got - are they for turbo or n/a? Turbo is useless for you at this point.

2. How much of an inspection do you have in NH? Smog, safety, etc.?? The Impreza has 2 oxygen sensors that'll need to be tapped in before and after the cat for the ECU to report the sensors as ready to pass an OBD II smog test. (Or just trick the sensor leads electronically, if you're into that kindd of thing.)

The L (and RS) Impreza has 2.25 pipes all the way back. You can use WRX/STI pipes, and it sounds like for you, if your cat is trash already, the easiest join with be from the cat to the mid pipe. Might as well just slap on a flange and weld it, and live with the sudden 2.25" -> 3" jump in the piping. Probably won't hurt anything...

"The L (and RS) Impreza has 2.25 pipes all the way back. You can use WRX/STI pipes, and it sounds like for you, if your cat is trash already, the easiest join with be from the cat to the mid pipe. Might as well just slap on a flange and weld it, and live with the sudden 2.25" -> 3" jump in the piping. Probably won't hurt anything..."

Very true, I fixed the exhaust made a custom adapter and it works just fine, sounds like a WRX matter a fact! I really like the system and the sound it produces! I wouldnt recommend it on another 2.5rs or L but in my case, Its amazing!