Slow_import

hey guys i've search but found nothing so i thought i ask, i just got a jdm p30 ecu from another member on the board and when i use it on my 00 si with a conversion harness, it gives me a check engine light, rpm bounces up and down at idle, and when vtec hits instead of the car starting to pull (like with the stock ecu) you could feel the car kind of lean forward like when you let off the gas at high rpms....

is there a sensor that i need to disconnect in the engine bay to stop this or whats going on....any help would be appreciated....