When I redid the vacuum lines on to reduce the mess in my old Civic, I encountered a problem like this... it was a result of T'ing off the MAP vacuum line thus not giving the MAP sensor a proper vacuum sample. It didn't throw a code either, but that was a pre-OBD computer.

Total MAP failure should throw the proper check code, however.

Have you checked the TPS sensor? It's a common cause of sudden bogging issues.