O2 Sensor problems of the 2017 Chevrolet Impala

Recently purchased this vehicle 3 months ago took it in for a routine oil change after driving it for several miles and filling the gas tank loud exhaust sound with an onstar diagnostic p0151 code appeared. Thinking there was water in the line I purchased heat to remove the moisture with no results. I proceeded to open the hood of the car for inspection and found the oxygen sensors lying in the cooling fans and the catalytic converter disconnected from the engine block. The plate was still connected with new nuts and bolts but the part looked rusted which seem odd for a car this new as a result of the heat escaping the engine block via the opening the cooling fans melted. I check for recalls on this model and there were none showing via several sources including the manufacturer's web site. The issue could have caused severe damage to the engine and electrical systems well due to the high temperatures from the engine block under the hood of the vehicle. The vehicle will operate and drive in this condition showing a check engine light on the instrument panel. What seemed odd was the bolts were shiny and the plate was discolored as seen in attached photos. The welds were also a concern as well.