Join Date: Aug 2016
Location: Central Oregon Coast
Here's my theory about leaving the O2 sensor connected after the flash. Long and short is don't do it. I think that after the flash if you leave the O2 sensor connected the ECU will still detect the presence of the O2 sensor and when all operating conditions are met such as engine operating temperature the ECU will go into closed loop but Ivan has zeroed out the O2 sensor data points within the ECU so when the ECU goes closed loop it enters into a state that is bogus which will adversely effect operation and might even be detrimental to the motor. So, disconnect the O2 sensor and the bike will not ever go closed loop but remain in open loop and obtain fueling and advance curve operating parameters based on Ivan's custom tuning which is exactly what you want. I also think that you should leave all CO settings at zero as instructed by Ivan. If you change the CO settings to +7, for example, I think you will richen the mixture by 0.5:1 AFR across the entire operating range because the bike never sees closed loop with the O2 sensor disconnected. With the O2 sensor connected the bike will not perform as it should without a load on the motor. For example if you warm up the bike then, with the trans in neutral producing no load on the motor, you open the throttle and try to hold the motor at any RPM above idle the motor will surge badly and even produce backfire. Just not a good thing and not good for the health of the motor. I suspect this produces an extremely lean operating condition so just remember to disconnect that O2 sensor after Ivan's flash and all will be good.
Well, this is my theory and I'm sticking to it! Am I still appreciative of Ivan's flash you may ask. YES, absolutely.
1993 BMW R1100RSL (mint)
2011 Ford Mustang GT/CS
2008 Ford Escape
Last edited by JamesW; 05-30-2020 at 01:51 PM.