If I need to change my catalytic converters would having one custom made with universal cats be possible/a good idea? Or would it just be better to buy a DEC converter for $360?

 

I would go to a local muffler shop and have them put a high flowbullet or race cat on. If you want they could do a whole "Cat-back" system while your there. Are you NA or Turboed?

 

Depending on your setup you might need 2 slim ones that stand up.

 

T6. I was thinking maybe for the money it might be a good idea to get a 3inch downpipe into 3inch magnaflows or something like that made up . Is there any point though if its going into the stock exhaust though? Nobody seems to make one for the s80 anymore that I could find.

 

You can try this link: https://volvoforums.com/m_38613/tm.htmit has a bunch off aftermarketsites.
http://www.heicosportiv.de/HEICO has a cat back set up, but it might be A lot of money.
Custom all the way back would be best.
3in downpipe to 3in cat, it will let the turbo spool better, and get more heat/gases away, but the stock partswill still have some restrictions.
If you can,try and get the whole system done.
Depending on the mods you do/or have done, I hear that a 2.5in from cat back should be fine.

 

For a cheap option, would it work emission wise, to just pull out the whole thing cut out the cats and weld in some universal ones? That seems like the easiest way to do it if it would work and not throw any codes.

 

It might work but I think you have the really slim ones that stand up.

 

It should work. My dad just did a custom exhaust on his BMW 540i with "race/bullit" cats and it passed California's emission. Just listen to Tech on what you you need.

 

As long as I can find some with the same dimensions as the stock ones should they work?

 

Yes they should.