I’m about at the end of my rope. I have a rzr 900s and ever since the muffler cracked on it a couple months ago I’ve had nothing but problems. I originally just had the crack welded then it started backfiring and you could only give it so much gas. It only does it after you ride it for a while. I have had it at the Polaris dealership nearby twice now. The first time they reflashed my ecu and said that was the problem. This time they but a different muffler on it, but it’s still doing it. They said they’ve sent three reports to Polaris and find nothing wrong? I don’t really know what to do at this point.