Since they are pretty much resonators, do they decrease exhaust tone a whole lot, or just a little.
www.cardomain.com/id/ashah000
well, you are going to replace the stock cat with a much less restrictive part. It's going to be louder.
from loud to quiet:test pipe -> high flo cat -> stock cat
i hate those ebay cats, even on a turboed car, ive seen them be really raspy. if you want a real hiflo cat, we sell direct bolt ons at http://www.exileracing.com/catalog/product_info.php?cPath=215_248_216&products_id=257heres a pic of it