there's a post on here awhile back from me about the terrible quality of those pieces of shit. I couldn't even use the test pipes, the flanges were clocked completely wrong with absolutely no way to correct it other than cut the pipe and re-weld it. Zero quality control in that chinese plant. Good luck with any warranty exchanges.
I have Specialty Z testpipes & catback now... side by side its like comparing a Ferrari to a Kia. Unfortunately, I am still using the Megan downpipes.