From the figure above shows there is something that is binding on the neck of the exhaust Yamaha YZF R125. . after the manifold,,,,. for it is indeed true. . . O2 sensor which is one important part Close Loop systems are generally placed after the manifold and in place before the "Catalitic Converter". . . for what? . . . if it goes after Kat-kon the O2 sensor readings be futile. . . not the result of combustion emissions, combustion emissions namuan that has been filtered by Katkon. . . when what is needed is a condition after firing. .. too fat or too skinny. . . whether the next Vi-Xion Close Loop will use the system?? . . . let's wait a while please chew chew snacks are available. . may be useful