She suddenly started idling very slow, and surging, When I got out and went around the back, the exhausts were emitting black smoke. When I got home, I left it overnight, and it seemed to be okay this morning, except possibly idling slightly high. This afternoon she was okay for a while, then started back with the surging and slow idle, At the lowest point, about 200 RPM the CHECK ENG message flashed on for a split second, Other than that, there are no warnings, and one of my OBDII sensors showed no codes. Haven't checked my other sensor yet, I'll do that tomorrow. At one stage I gave it heaps, and it appeared to be quite good for a while. When I got home, there was no smoke, but there was quite a smell. I've only just now thought , I wonder if the cats might smell through working hard because of how rich it was running, Could that be the case?
Any thoughts, anyone?