Anybody know if an intake alone will cause the bike to run lean? How about an exhaust alone? By alone I mean no other mods or fuel controller.
Yes, by design an aftermarket intake/filter is allowing more air into your engine and will tend to lean out the already lean fuel/air mixture. After warming up in open loop, it will switch to closed loop once certain conditions are met. EFI will compensate to a certain degree but you may still notice some drivability issues. A fuel controller will alter the mixture to work better with your new free-breathing hardware. So to be safe, a FC should be installed when you start swapping pipes & intakes.
And FYI, you can fit another wideband O2 sensor in there, but it's a little tight. I made a custom 18mm adapter for the Bazzaz Z-AFM since all I found were too short.