Ok here's the deal I just got a JDM GSR swap I was running an ODB 2 and it kept on throwing error codes 71-74 (random misfires) when I paid for the swap I also bought an ODB 1. I was running an ODB 2 to pass inspection (which is overdue yeah NJ sucks like that, I have my car registered in NJ)

I finally said the hell with it and put in the ODB 1 and viola no CEL. Does anyone have an insight as to why this happend? I am thinking that my engine is older and is supposed to run an ODB 1. Other then that I am not to sure why this would solve my probelm. Unless there are different sensors in the ODB 2 is looking for and are not in my motor.

 

The OBD-1 ECU doesn't watch the CKF sensor, so it doesn't have any way of 'knowing' about the misfires. So it didn't really solve the misfires.