Car is a 2000 Civic Si

I have a 4-1 Header with a 2.5 collector. As we all know the 2.5 collector doesn't bolt up with the stock cat. So i have been researching this and im not sure what to do.

1. Should i get a test pipe and o2 simulator
2. Should i get a p28 OBD1 Converstion

I also have a extra OEM Gutted Cat can anything be done with that???

I am open for other options if you can help please do. All input is appreciated. Thanks




Modified by chameleon30038 at 6:24 PM 10/6/2005

 

You can also get a 2.5 cat like a carsound. They come with the secondary O2 bung so you can still use it. The only thing is having flanges welded to fit.

 

get a 2.5 carsound cat or 2.5 testipe, 2.5 custom piping, and 2.5 in/out muffler.

 

Well i wanted to purchase a cat-back. I currently have custom piping w/ Greddy Evo.

I would be kinda pissed if i have to buy another cat because i just bought a OEM Cat right before i bought the header cause i needed to pass inspection. I have a Gutted OEM Cat can anything be done with that?