This is not exactly true... The Dynojet PowerCommander V Autotune module uses the existing O2 sensor hole. You replace the stock O2 sensor with a wide band sensor, but you do not use both. They do have a dual channel Autotune module... but it is for bikes that came equipped with 2 O2 sensors. here are the instructions:Kov68 said:
http://www.powercommander.com/downloads/UserGuides/AT200/AT-200.pdf
Also looked thru the Stryker service manual.. it says the O2 sensor is an M18 thread size...