As I research the make and model of my car, a '96 Mitsubishi Legnum I find that the check engine light coming on is a regular occurrence. Any ideas or a check list of possible reasons that I may be able to use to eliminate this problem.
Get yourself an OBDII code reader. Buy a cheap one you don't need anything special. I've seen them as low as $15 Cdn and wouldn't pay anything more than $30 Cdn.
Plug it in and follow the directions.
It plugs into this thing here...
Once you know what the code is you can clear it and then go find out what it means.
It is telling you to check levels etc under the bonnet. Once the light is on then something needs your attention.
If you can get the codes read, then that may help us point you in a direction - as just the light is on does not narrow down which system.
It probably is just coincidence that this has started to happen at the same time that you start your research.