Help, can't read codes.
 

I recently swapped a JDM 98 spec ITR in a 98 civic ex. Runs great, but can't read the error codes, not even jumping them. I brought it to a pro mechanic he said that there is either a power or a ground that is not connect correctly to the relay where you would read the codes. I have plugs that don't connect to the JDM motor that were on the original d16 like the IAT sensor, that is looking for a return signal. I know this because it is hot. Would this have something to do with the harness connection to the computer, ie pinouts on the ecu. Oh, it is a p73 ecu. Plus I don't have a oil pressure sensor on the vtec sulinoid, so that plug is not attached either. It has no problem going into vtec though.

A little insight would be very helpful. I'd like to get rid of that check engine light.

Thanks