Idles ok when it misfires only drops maybe 20rpm so small you cant tell on gauge. New plugs wires cap rotor fuel filter. Unplugged each plug one at a time all 4 had a big change in idle all have spark no vac leaks egr good. What could cause this minor misfire and not a check engine light higher rpms the bigger the mis unless im full throttle.coolant is good no problem there temps all good. Only use premium dont matter where i go. No change in idle with weather. Seafoam helped a little but not enough.

 

Clean out throttle body very good, spraying intake cleaner in while operating throttle by hand. Also pull your pcv out and clean. You should probably clean iacv, too.