I know that the oil pressure is OK by the simple fact the car has run for 5000 miles since I made the mistake of starting it without the fuse with no problem
That's brave!
You could have lost the supply to the OBD socket, check pin 16 for +12V. The supply often comes from a fuse which supplies multiple circuits, possibly including sensors, etc.
Some generic readers are not compatible with some vehicles, particularly those using SAE J1850 protocols, but I've never had any problems with Japanese cars, including the Honda. If you can't get it to work with 5 devices, there must be something amiss.
If everything looks okay at the socket, you could have a wiring problem back to the ECU, or even a faulty ECU.