Gutted pre-cats will also lead to rasp.
When I installed my msds headers, I also installed a WR y-pipe and trubendz cat (not gutted). It is possible that what I'm hearing is drone and not rasp, but I had gutted pre-cats (waste of time) for about 6 months prior to installing the headers and stuff... and it did rasp/drone then too.
I'd hope Canada is colder than here.... I think pretty much everywhere else is colder than Phoenix
