« Last post by m1shooter on Today at 10:38:45 PM »
You get it. The stock tune is looking for values between X and XX. When you free up flow and reduce concentrations lower than X, the stock tune can't do anything about it because it isn't set that low. This is no different than changing jets in a carb setup to compensate for changes in elevation, air intake, or exhaust. Someone that lives near sea level and a lot of humidity like myself and the OP may not see any issues related opening up the exhaust because of air density whereas someone living in the high mountain desert may find their bike unridable with the same tune and mods.