to make a long story short my 98 civic was coverted to obd1 for tunning reasons. now i need to pass st. louis emissions. i purchased an obd2a jdm p73 because i dont have a second o2 or evap or anything. engine runs fine but no scan tool i can find will communicate with it. obd port has power and ground. any ideas?

 

JDM ECUs do not have the hardware nor software to communicate to USDM scan tools.

you need a USDM ECU.