Slight stumble at idle. No other symptoms
 

I am having a slight stumble at idle, it idles for maybe 30 seconds then stumbles down and up, 30 seconds down then up. All between around 700-900 rpm.

This is a new to me car with 94k miles.

Clean MAF sensor?

Just bought a 2001 S with exact same issue, except mine had a slight delay/breakover on throttle as well. Pulled and cleaned the throttle body, it's tube, and vacuum valve crossover tube behind it. Really easy really, had them done in about an hour or so. Watch the little plastic hose that plugs into the vac crossover tube bushing. oil it before reinstalling it after cleaning. Problem all gone, perfect idle. Heard that it can sometimes be the MAF. I didn't need to touch mine though. Wipe out tube passages with rags, and clean Throttle Body with Carb cleaner and rags, thoroughly, reinstall.