Hi, welcome to Just answer, my name is Ross, I will help with your question.
Ok, is this misfire there all the time?
Yes they can cause problems with the ECU, it can blow the control circuit on the main board, do you have access to any diagnostic equipment to carry out a fault code scan?
Ok, yea to be honest without a fault code its difficult to pinpoint what's causing a misfire but it does sounds like it may be the signal from the ECU as you have changed the usual suspected.
Hopefully the new ECU will cure this fault, it would certainly be the next place I looked to replace. If you need any further help with this please feel free to ask, I will be happy to help.
Hi please let me know if you need further assistance with this problem i will be happy to continue my assistance.