So I kept the Rv6 header and reset my ecu to stock with the hondata and that resolved the cel and p0400 error. I was able to pass deq. I'm guessing at this point it is an issue with the base map causing the cel.
I'm running into the same issue currently and I need to be able to pass deq so I can't turn off the egr to eliminate the cel. If you have any more info or help I would greatly appreciate it.
David