I have a b18c 96 spec itr swap in my 99 civic i was wondering can i read my check engine codes with a p28 it currently has a p73

 

The codes are not going to magically transfer to a different ECU. As well, you may get different codes altogether with the P28.

Swapping ECU's is likely going to defeat what you want to do and that is get your current codes.

 

so i have to do the pin trick ?

 

As far as I know yes. If it's a USDM P73 then a scan tool should work too.

If it's a JDM P73 then only the service connector and counting blink codes will work.

 

If it's a USDM ECU, you should be able to plug a code reader in and pull codes. If it's a JDM ECU, you have to jumper the service connector. If you swapped in a P28, not only would it not run the engine correctly (and would risk detonating it into scrap metal), you would still have to jumper the service connector.

Just jumper the service connector. Stop overthinking it.