Intermittent misfire

2016 Focus SE. Got a code from O2 sensor. P2195. Running rich intermittent misfire. I cleaned the MAFS and connections with proper cleaner and changed air filter. Seems to have worked for now but might be stuttering at idle in gear. RPMS drop below 500. Also at start up idle is about 1200 for say 20 seconds. I'm in Tacoma, WA. We had alot of fore smoke the past month. Any tips? Just want to be prepared if the engine light comes on again