I have a 1994 Civic EX Coupe, with a JDM b18b block and a b18c1 heads and intake......someone had mentioned to me they had looked at the car before and there is an issue with the butterfly plate, it still has the stock p22 ecu and its throwing a code for an oxygen sensor and nothing else, now my question is....what is the butterfly plate and could it be the problem to my code????

 

If I had to guess on the the "Butterfly plate" I would say that it has to do with the Butterfly in the throttle body. Why it would have a problem is beyond me? So assuming that I would say no it has nothing to do with your O2 sensor.