So I have read some forms and they explain that with a slip-on exhaust there is no real need for a/f tuner of any kind because the 02 sensor adjusting the ecu. My bike has no o2 sensor (not California model) so do I need to get some kind of tuner? What if I get a k&n? I left in the baffle on my danmoto so I don't lose too much back pressure. Is there an alternative for a pcIII? Cheaper hopefully.