i did a b20b swap (with LS IM) into my eg coupe... im running an obd2 ecu (with 1-2 adapter) and motor.. its throwing a CEL.. and i think im supposed to be running 2 o2 sensors.. is this correct?

if i am.. where do i add one in onto the harness?

also.. if its easier.. i have an obd1 ecu i can run.. if i do that what would i need to change to make the motor run correctly?