my exhaust light came on and went off something like 24 hours later...never happened again. take to an indy if you are worried, they often hook up diagnostics and dont charge. Unlike a main barsteward stealer who often charge labour to diagnose, then talk a lot of nonsense about the potential faults, book you in, change a few unrelated things, then in the meantime they reset the fault and say its fixed, whilst charging you dearly for the priveledge.
If you dont want to be paitent then go get it reset, if it comes back investigate further.