Wow a quick response back.

It is going to be pretty hard to show a leak. The only way I could see it is if black soot along with condensation was coming out and staining the muffler. This might take a while to happen.
You have the SJJ21R kit? Correct? ?
I will send you out a replacement muffler.
What is your "complete "full name, address and telephone number?

I offered to test it and they responded right back with the following.

That might work but I don't want you to go through all of that effort. If you say it is leaking there then I will replace it.

They are definitely a stand up company.

on another note not a long term test by no means but fuel report after a full week of normal driving and my average MPG is up by 1 MPG.