HECTIC

Ok heres goes.. I did a quick search but couldn't find what i was looking for..
I have a 1998 Civic coupe HX w/ an 96 LS swap.. It's throwing a 65 code. so I thought easy enough we'll just switch the O2 sensor .wrong.. I replaced both O2 sensor with brand new ones.. code still there.... then it seemed that the engine wiring harness had been done incorrectly. So I purchased another one and replaced that as well.. code still there..... so I thought maybe the messed up wiring harness had shorted out the connector pin on the ECU. So I replaced the ECU w/ one from a 96 Integra LS.. code still there....so im strating to run low on cash and ideas.. Ive been told to try replacing the Catalytic Converter but have been unable to find one within my price range..

any other ideas would be great...