hesitation when maintaining constant speed

Do you have a check engine light and when was last major tune-up??

Could be caused by one of the following below

Oxygen sensor.
Catalytic converter.
Fuel injectors dirty/sticking.
Mass airflow sensor/Airflow meter.
Throttle position sensor.
Crankshaft position sensor
Knock sensor
Manifold absolute pressure sensor.
EGR Valve
Fuel pressure regulator leaking or defective fuel pump.
False air leakage.
Fuel contamination.
Foul/defective spark plugs.
Open spark plug wires.
Ignition coil/Coil packs defective.
Incorrect ignition timing.
Cap and rotor.

Note:If it doesn't apply disregard it

so basically every item related to the electronics you have indicated may be the problem...? No check engine light has been on, only recent maint work has been oil change, air/fuel filter. Transmission filter/oil change

Each and one of them could cause your problem don't always rely on the computer to pop code/s for a starting point in your case you need to troubleshoot to get to the problem area and what caused it-