Hi guys,
Since the stock exhaust is terrible I've been looking for a new muffler, but unfortunately all the aftermarket exhausts are too expensive for me, and they're illegal to use in my country. Then I found a local (Hungary) exhaust maker who made me a beautiful muffler with a pipe which connects to the stock manifold. It cost me around approx. 240 dollars and not only is it street legal here, but it also uses the stock O2 sensor. Since it's a completely open muffler (but there's a dB-killer installed), I am not sure whether it affects the bike's performance. My dynobutt feels no difference, maybe a very very little less torque. With the O2 sensor installed, can the bike adjust itself to the new exhaust?

 

It is unfortunate that the closed loop "self adjusting" aspect of OEM EFI systems has become FUBAR in, and by, the public sector ...

Closed loop operation will use the O2 sensor to maintain 14.7:1 AFR. This is for emissions compliance and, to a lesser degree, fuel mileage..
Open loop engine operation does NOT use the O2 sensor and has no "self adjusting" capability.

Closed loop ops DO NOT include: Idle, high throttle settings, moderate to high accelerations, any performance engine operation..

Closed loop ops DO INCLUDE: low speed, low throttle operation, Steady speed cruising using lower throttle settings (usually under 1/2 throttle) ..

O2 sensors and Closed Loop algorithms were introduced into OEM EFI systems in order to pass emissions testing. The operational envelope of closed loop is designed to encompass the engine operations that are used during emission testing. PERIOD !

If you mod your EFI bike for more performance, you must modify the fueling.

 

Thank you for clearing that up. I'm aware that I can't get more power without modifying the fueling, but that wasn't my goal. I was just wondering whether the bike can adapt to the new exhaust without having any problems.

 

Without any intake mods - using only the stock induction configs - the slipon alone should not cause issues with closed loop or open loop fueling..