ok so heres the deal after ripping out my interior the other night my buddy saw my ecu was flashing once, code 1 which is the o2 sensor i believe. but anyway if im driveing get my car into 5th and go above like 85 my engine light will turn on. now if i shut off the car and turn it back on the engine light stays off and will remain off untill i go above 85 again. the car is a stock 90 crx si no major mods. would the ecu throwing that code make the engine light go on like that, and is the fix just to replace the o2 sensor? thanks for your help guys.

 

yes cause the o2 doesnt send a signal till its warmed up. and yes replace it.