The car is running great but the engine light is on.
My car has 103000 miles.
My car has an automatic transmission.
The oil change process is generally a very simple one, but it does involve moving panels and some shops do a brief inspection on the vehicle as well. It is not likely that the Check Engine Light coming on is directly connected to the oil change service, but there is a chance something may have been bumped during the process. You should return to the shop, inform them of the concern and ask if they will at least scan the vehicle to see what code has popped up and what steps should be taken to correct the fault.