Okay, I had the same thing. Turned out some spines in the distributor for the tdc sensor were shot. With you ECU, do some engine code searches. I dont have my book on my so i cant help you except that the 20 is for you electric load sensor. SI's and integras had it but dx and hfs didn't. I supposed to be in you engine bay fuse box but there isn't one there. Don't worry once the other codes are gone this one does not show on the dash and will not effect anything. I have driven 3 months on engine and it fine. Talkto honda dealer and they said don't worry.