AHHHH my check engine is on in my 91 honda civic and autozone dont have the hand held to hook up to it but someone said its only 1 of three things o2 sensor maintanance schedule and soem cylinoid how can i find out what it is and where can i find out how many blinks equal what on the ecu

 

Look at the ECU, it's under the carpet in the passenger footwell. Count the number of times it blinks, that's your code, you can find what it's for in this forum's FAQ. And since you're OBD0 you won't have a "scanner" you can plug into, the guy at Autozone was right. And it could be one of many things not just 3 .

 

Pull out your passenger side carpet, the ECU is located right under the carpet. Let me see if I can get a diagram.