Catalytic Convertor problems of the 2017 Lincoln Continental

The contact owns a 2017 Lincoln Continental. The contact stated while at various speeds, the contact noticed that there was an abnormal burning oil odor coming from the vehicle. Additionally, the contact stated while driving at various speeds on several occasions, the vehicle made an abnormal grinding sound, unexpectedly bounced and stalled. The message "4wd off" was displayed. The vehicle was towed to different independent mechanics, and the transfer case was replaced twice; however, the failure persisted while driving. The vehicle was taken to an independent mechanic, where it was determined that the transfer case needed to be replaced. The vehicle was being repaired; however, the contact expressed safety concerns that the repair might only be temporary. The manufacturer was not contacted. The failure mileage was approximately 110,000.