tomascs

ok i have a 97 hb cx
about two days ago the check engine light went on and i took the car to my friends shop
he tried to connect his computer to my ECU but it couldnt stablish a connection with the ECU in my car
so i had to get the ECU to blink me the code to find out what was going on
it ended up being that the o2 sensor wasnt working right so i got that fixed
even tho i got the problem fixed im still trying to find out why the computer wasnt able to stablish a connection with my ECU
does anyone have any ideas
or has this ever happened to any of you
by the way the ECU is a p2e co3