Oklahoma will host Florida Atlantic on Sept. 1, 2018. That completes their non-conference schedule, also host UCLA and Army.
http://www.fbschedules.com/2015/04/florida-atlantic-play-at-oklahoma-2018-illinois-2020/
http://www.fbschedules.com/2015/04/florida-atlantic-play-at-oklahoma-2018-illinois-2020/