120k on the car
all maint is always done regularly.
oil changes..spark plugs..wires...etc

the car has always had a rough idle and i heard about lucas gas treatment and i put about half of one of the big bottles
the car runs great
i also have been mixing the gas i put in like sometimes ill put in a lower grade and sometimes higher..premium is nearly 4 dollars a gallon here

so anyway i was driving last night and my cel came on
car still feels fine starts right up
was this caused by all the mixing of fuel that i have done and even possibly the fuel treatment?
thanks.

also my gas cap is not loose haha

 

The first step in diagnosing why the check engine light came on would be to retrieve the code...

https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/how-pull-cel-d4-srs-abs-codes-code-lists-1901557/

After you have the code(s), let us know and we'll be much better at helping you diagnose the problem

 

thanks bro