My 2000 SE had some issues right after I purchased it. The CEL started flashing and the car ran very rough to the point it would not make power to move. Not knowing how important it was to stop and fix it, I got it to limp home.
The code was P0300 and the problem turned out to be a coil pack. I purchased a new coil pack, installed it and reset the CEL. I also replaced the plugs and installed Magnecor plug wires while I was working on the ignition.
The first trip out I started getting the dreaded P0420 code. See that repair below.
Bottom line, I learned to STOP driving if the CEL FLASHES.
My 1999 AE started flashing the CEL a few months later. So, I immediately pulled over and made arrangements to retrieve the car with my trailer. Once home, I found that I had another P0300 code to fix.
I had already purchased a used coil pack since the first problem. I installed the used coil pack, new plugs and new plug wires. Great, the problem was fixed. I kept my fingers crossed the CAT was not ruined. Thankfully it turned out to be fine.
Now I keep a spare coil pack on the shelf.
Again STOP driving if the CEL FLASHES at you! It is trying to help you!