ok well i have a 99 GS-R , all stock...no mods but a AEM filter on the stock piping...well today the Maint Reqd sign came on, i figured low oil...and indeed it was low on oil , put in 3 quarts....but the maintenance required sign is still on...anyone know what it could be???

i had advance auto parts check it with an OBD2 scanner but no codes...