I have been running a Drummer and stock ECM. The bike ran fine but accelerating never felt quite right compared to my 12S/stock exhaust. There was always lots of popping on deceleration and engine braking.
I installed a pre-programmed Erik Buell Racing ECM and the bike runs PERFECTLY now. Acceleration is smooth and there is no popping on deceleration or engine braking. I can't believe I waited this long to replace the ECM.
If you are running an after-market exhaust and putting up with popping and crappy performance reprogram or replace your ECM!
I just posted this for those of you who needed to hear one more person happy with the results of a new ECM.