Check engine light 1990 Honda Accord EX automatic?

So my check engine light comes on when I'm driving then when i turn the car off its gone. I don't have a scanning tool so i try using the jump wire and all i get is one flash every 4 seconds Its a one second flash then it flashes again after 4 seconds have passed.

You can take your car into nearly any major car part store pep boys, checker, autozone, o'reilly's and they will scan it for free. Yes when you turn the car off the light goes away.

O2A oxygen sensor. You must have two oxygen sensors. Look up which is A or B.