Volvo 245 has developed an intermittent rough/stumbling idle and the car often stalls while driving if one shifts into neutral coasting up to red lights, etc. I would greatly appreciate any help or advice someone might have to resolve this issue. When accelerating or moving on the highway in gear the engine does not miss or have any issue.

Things I am considering:

Replace air filter ; make sure the throttle body hose is clear, etc.
Possibly consider removing the Mass air flow sensor and throttle body and cleaning appropriately. Does anyone have advice for how to do this? Or things to avoid?

Thank you very much!