it seems odd the car should run like that if the dealer performed all regular service.

nevertheless:

inspect/clean the flame trap including the small brass nipple on the intake manifold which the small flame trap hose connects into

once clean and or replace the vacuum hoses if you have a vacuum gauge hook it up the a vacuum line through a T so no lines are truly disconnected and ascertain if you have any vacuum leaks. the gauge will show or should the vacuum pressure area for normal operation

use a multimeter at the o2 sensor connection at the firewall. do not disconnect the sensor merely tap the live voltage from the signal wire (white i think) and see if swings actively between .4 and 1 volt after the sensor is fully heated up. if the sensor swings lazily or inactive or dead you might want to replace it.

you might want to clean carefully the idle control valve and make sure it opens and closes properly..located under the intake in its own frame. same with the Throttle Position switch located on the back edge of the intake manifold where the air duct is fastened.

the mileage is so low and with its service history i can not imagine there is anything seriously wrong. sounds like a vacuum clog or leak and maybe a tired o2 sensor.