i have a 91 integra ,usuallly when i when i drive in the freeway and reach 4th gear my check engine light comes on. Also while driving i notice that my oil light keeps blinking but there is plenty of oil in the car and there is no signs of leakage would anyone know what the problem could be?

 

have you brought it to a dealer or checked the transmission lately? also you made need to check your oil pump...just a couple suggestions, i never had it happen to me before...
WolfGang