RPM's???? 600 RPM too low?
 

Excuse the noobie question but what should the idle at rest a 2000 2.7 Boxster. I just had an O2 sensor replaced and the RPMs feel too low and quiet. Idles at 600 RPM with or wothout AC on once warm to 180. Is this normal? Maybe it's fixed and I'm just being paranoid. Or possible other O2 sensor or MAF??

that is perfectly normal for a stock 2.7 to idle at roughly 600 RPM. Mine was that way until I retuned the ECU and bumped my idle up to 850 RPM. 600 was too low for me. I also changed my redline to 7500 RPM.