RZR S 900 636 code and cutting out up bumpy hills. September 13, 2015 I don’t understand whats going on. After I had this muffler welded. The last three rides I’ve went on it’ll cut out with going up bumpy hills. It got real bad on the second ride and threw a 636 code, but then it went away. Could it be my muffler? Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window) Related