What year is the engine your installing. Also what year distributor and injectors? You need to make sure everything is obd-2 if your running an obd-2 ecu. And also if it is a jdm motor you will need to swap over a lot of pieces from a usdm motor to get rid of your cel to pass emissions. Unless your running a jdm ecu. So many variables, the only thing I can tell you without knowing more is check your ecu, coil, and rotor.b