I’ve been searching around, but can’t get any straight answers from YouTube videos and other posts.

i recently bought an Evo 8 that’s been straight piped by the previous owner. I don’t really like it, and on top of that, the car won’t pass VA state emissions as is. I’m ready to order another exhaust with cats, etc, but don’t know exactly what to order. Exhaust diagrams are available, but they only show me stock parts, which I don’t really want to go with.

What are some aftermarket parts that I need to replace my straight pipe completely?

 

The majority of aftermarket exhausts will be
1)downpipe
2)cat (or test pipe) and
3)cat back all the way to the muffler.

some cat backs are two pieces and some have a resonator. But for the most part it is those three main parts. The cat and cat back section will determine how loud (or quiet) the sound will be.

 

From turbo, your have downpipe, catalytic converter, and cat-back exhaust (mid pipe and muffler).

 

4 parts- O2 housing that bolts to the turbine housing, down pipe, test pipe (or cat), and the catback exhaust.

 

ahh yes, the O2 housing is something to check too. If its been replaced it might not be stock fitment.

 

Only a few O2 housings aren't OEM Fitment, and they usually are sold as a complete setup with a down pipe. The main concern for passing emissions will be having a cat, and depending on the state a cat back that isn't obscenely loud.

 

this is exactly what I was looking for! Thanks for all of the responses.

 

I'd recommend against a one piece O2 eliminator downpipe. A lot of companies offer them but they are a PITA to install/remove with the turbo on the car IMO. This is the one I have and it is very simple to remove the downpipe. Just something to keep in mind when exhaust shopping.