Engine light came on got it tested then went off after test .if it doesn’t come back on does that mean everything things ok
Generally- -Yes. CEL off indicates systems are functioning correctly.
However, if you have the code numbers (P0123). Will give us a clue to original problem. Who can say when the fault detected will reappear, maybe tomorrow, maybe never,
It means whatever the problem was, no longer exists
True that, but that does not mean it wont come back. If you have the code, post it here. There may be something you could do now, or at least at your convenience in the near future to prevent a inconvenient problem later.