Today while giving a friend a lift in rush hour traffic, the ! lights and the oil pressure light started flickering, though the car continued running. On the remainder of the trip, I got nothing. The only difference is she wanted the AC on, and I had it off with the sunroof open and the windows down afterwards. I want to say the car's idling too low and maybe the load from the compressor belt had me close to stalling - is that it? What should I check?

Emanuel