Bones,

I chatted with Horizon tech support also and ask them if the new muffler had corrected all of the issues with the old muffler and he had no idea there was even a new muffler being used on the latest 15gx. That is why I decided to go with the OS GT15. I hope you can get your muffler fixed or even replaced by Horizon. It is a said thing when you have to go out and spend more money to get something corrected on a new engine