Hi im from australia and got a defect by police. long story short prior to this my bike has hooker trouble maker pipes, se stage 1 flash tune, se stage 1 filter. To clear my bike from defect i put the standard exhaust on. when i started it, it backfired and bit of smoke around the exhaust outlet or o2sensors and aircleaner.. any idea?? can you have that air cleaner run with a standard exhaust cause i dont mind the look. thanks