I need to switch out my P28 to a Po7 so i can pass inspection will i need to reflash the computer since i am running a d15z1 with a Po8 head so i can run the o2 sensor or should i just rewire the harness so i can run the 4 wire o2 sensor only reason why i ask is because would it be a problem to run the Po8 head with the Po7 ecu since there is probably different programing involved for that head.