Additional follow-up: Started her up this morning, and (unlike last night, driving to Advanced Auto) the CEL appeared again. It flashed briefly, then became a steady light. Talked to my usual mechanic on the phone, then drove into the shop so he could test it.
The read-out indicated 'misfire, cylinder 1', which he said could be either ignition-related or fuel injector-related. (BTW, when he switched his tester to generic, it---like the tester at Advanced Auto---also read 'no codes'. So, heed Mike Focke's discourse on "CELs in the Boxster" wherein he says: "Be aware that there are codes that the Actron can't read that could be helpful in diagnosing a problem that a Porsche System Tester 2 (PST2) or the later PIWIS can. Dealers have these system tester and some independent mechanics specializing in Porsches have them."
My guy at the indy shop said as long as it's not flashing, it's OK to drive for a short while until I can get her into the shop, but watch for the flashing CEL. He said that it flashes when the misfires are actually occurring, and that's where the serious danger to the catalytic converter exists.
I'm new to all of this. Any comments?
BTW, the only reason I'm driving the Boxster at all at this point is because my other car---a Toyota with 185K miles on it---is getting checked out. I've never before simultaneously had TWO cars that had CELs displayed. It kind of sucks...
