OK... I found out how to get rid of my ELD cel code 20. Last night I finally wired my secondary oxygen sensor and both codes dissapeared (20 and 65). As I was wondering why... I realized that the oxygen sensors on obd2 hondas have 4 wires. 2 for the actual oxygen sensing and the other 2 are for the oxygen sensor heater. Since the ELD senses the ''total'' electrical load, it was seing that the circuit for the secondary oxygen sensor heater was open. And that is why it was throwing the code. I'm sure as a quick fix, I could have just connected a resistor between the two oxygen sensor heater wires and the cel code 20 would have dissapeared.
HMmmm... sounds like a test I will have to do in the future.
I guess the conclusion from this is that to get rid of this code... you have to make sure that every important component drawing current from your battery must be connected.
Hope this helps.