I know that straight pipe's in place of the catalytic converter with no catalyst grid in the pipe are real loud for your exhaust but are those high flow cat's that are shaped like a straight pipe in a way loud? I am thinking of getting one from my friend for cheap. I would go for those carsound cat's because I had one on my 90 max but I will like to know if these high flow cat's like the one in the pic are loud and nosiy like the straight pipe's. I like to cruise, not set of alarms

 

I had a hi-flow cat and paid almost $200 for it but it don't compare with my home made punched cat. If you have a good muffler ie 2k etc the no-cat noise is acceptable.

Take your pic, I am not an environmentalist by any means but I also don't want to take down the planet. I use the straight pipe for racing and in my punny little mind thats acceptable.