Engine Head Gasket Leaking problems of the 2012 Kia Motor Sorento

When me and my husband purchased the SUV used in 2016 from a huyndai dealer that is local, there has always been a sensor lit that we had no clue what it was. We were never told anything about it, they told us the vehicle was in good condition that it was inspected and everything. We took the SUV to kia in 2019 to have the oil changed, and had them check the motor to see if they could explain why we were going thru oil weekly. While we were there the service person told us that the OCS mat does not function that it needs replaced and that is what that sensor is for which we would have not known and the dealer that sold it to us never told us anything. I figured it was a weight sensor for a child as I am not an expert on the safety of vehicles. . . . Also, we were told that when the dealer sold us the vehicle as is that they never had a safety inspection done prior to put it on the lot. The last documented safety inspection on the vehicle was done when it was sold brand new when the first original owner bought it from the kia lot I believe in another state. Kia told me that they have to do the safety inspection before selling it on the lot because a non kia dealer sold us the vehicle. I did contact California state about my complaints and was told there was nothing that I can do to prove I didn't cause it but I have never been in any accident in the SUV that would cause the airbags to go off. . . . . I am driving daily with my children in the car without working airbags. I cannot afford to replace the OCS mat and I believe I shouldn't have to. Also, we have had issues with our gasket that we had to get fixed, we are constantly going thru oil and we only drive it around town. We are having to add oil in it every week so the engine does not blow. We now have a vacuum leak in the gasket.