Two questions from reading the forums:

Is there a way to test if any one of the ignition coil is bad without the ECU flashing an error code? What are the steps to test?

Are the 4th generation Coils compatible with the 5th generation ignition coils? or vice versa--taking a coil from a 5th Generation engine and using it on a 4th? The specs and sizes of the two engines are very similar which leads me to believe that it could be done, but wasn't sure if anyone has ever done so up to this point?

Thank you,