Join Date: Sep 2008
Location: Honolulu, HI, USA
I installed the approved NTK 02 sensor and noted no difference, but as it turned out the sensor was not the cause of trouble on my 30kmile 2010 K1300GT. IIRC I got the new sensor on sale from Euro Motoelectric, along with four coils and plugs, none of which helped. In the end, it was the fuel pressure sensor on the fuel rail that had faulted. The dealer's tech discovered this by connecting a fuel pressure gage to the fuel line - very old school.
I spoke at length with the dealer tech about the electrical and mechanical functions of the bike. He confirmed there is no customer-available technical information and that the present course of BMW Motorrad is to turn dealer mechanics into parts replacers, dependent on verifiable connection of customer bikes to Motorrad HQ.
The bike runs an alpha-n injection system, meaning that the prime parameters input to the ECU are throttle position sensor and crank speed. Injector opening duration (pulse width) is modified by the intake air temp, local barometric pressure, and coolant temp. The fuel pump runs constantly and provides constant fuel pressure. The fuel sensor only verifies correct, constant pressure. The ECU has no ability to recognize engine load. When the engine comes under load, the rpm will drop unless the operator increases throttle opening.
I have been told by a person whose information is believed good, that resistor tuning devices ceased to be useful/appropriate a decade ago. That person did not further qualify his statement.
OP, my bike (also) gets at or just under 30 mpg on 87 octane at sea level town driving at ambient temps in the 80s-low 90s. OTOH I live on an island of a million people and even more cars, that is only 20 miles long and 30 miles wide.