@IsbCap you are lucky to get complete engine with orignal ECU. My F18 B had ECU from F23A VTEC. And Guess what that engine came with Knock Sensor. But F18 B did not had.
The guy who installed the engine thought that well ECU is there Engine is knocking and he retarted the ignition timing by Crank Pulley (Idoit guy). And when it did not stoped he cut the O2 wire to make it rich...........
when i got car I knew nothnig about car and now i did everything, ecu swap, wiring. engine wiring and sensor checking, throttle body , Fuel Injector , fuel regulator what not man., And these days i am working out the timing belt adjustment.
To my amazement no one tried to understand the logic behind the problem and everyone kept blaming others.