Here some info on my 97 CIVIC EX.....

-99 SI motor B16A2
-97 GSR Tranny
-96-98 GSR ecu
-Right now my car still using 96-98 ecu harness..

Has DC 4-1 header, Tanabe cat-back, AEM cai and AEM fuel regulator. Right now the car is very slow.... can it be the GSR ecu effect the performance?

I wanted to convert it back to OBD1 with the adaptor OBD II to OBD l. But can I use a JDM p73 JUN programmed ECU with the adaptor just plug and play or JDM and USDM ecu's are different? And will not plug into the OBD I adaptor? Since my motor is stock can I use the JUN programmed ecu? Can it harm the engine? please let me know ........thanks for your reply.....