Most OBD2 Hondas until the RSX, 06 Civic, and 06 S2000 have a fixed ROM.

ODB1 conversion (which is chippable) is possible for those ODB2 cars but not for every car under the current rules because the its a different sized case, internal board, and ECU connector type. Honda or Acuras that have OBD1 and OBD2 cars on the same spec line can revert back to OBD1 with update-backdate.