There is a 6pin to obd2 adapter cable for certain hondas.

However, with my 98 Odyssey (obd2b), i tried this adapter, and it did not work. I was looking into wiring certain ecu wires to a obd2 female plug, but never got around to it - I also vaguely recall that the data protocol was different to the typical obd2 one. Wouldn't surmise me if the HRV is the same deal.

The actual bluetooth dongle thing I successfully have used in my DC5R and my GE8 Jazz (direct connection, didnt need a adapter cable).