Yes, using 92 octane gasoline in a Cadillac can negatively affect the vehicle. It can cause engine knocking and, over time, potentially damage the engine.
An occasional fill-up with 92 octane gasoline is unlikely to cause significant harm, but it is best to adhere to the fuel octane rating specified by the vehicle manufacturer.
The difference between 92 and 95 octane gasoline is relatively small. Both grades are generally interchangeable as primary automotive fuels. As long as the incorrect octane rating is not used for an extended period, it is unlikely to cause damage to the vehicle.