yea the only time i have any problems at all on the east coast is when inspection/emission time rolls around, but you can usually buy one easier than you can make one, i am a fabricator but didn't wont to come up with the mounting flanges due to the ball/socket gasket coming off the header, and here i have a contact at a junk yard and he wont even sell me a convertor just for the flanges? you can however gut out your stock one and do the same as a test pipe, but of course you have to have a back up plan just in case