For those that have been following my plight, I am continuing to get misfire codes along Bank A and specific cylinders.

Can someone explain to me "how" the ecu/bcm "knows" there is a misfire in a specific cylinder(s)?

 

When a cylinder misfires the crank rotates unevenly. So the ECM compares the crank and cam position to calculate the misfiring cylinder

 

Fantastic explaination Leaper! Thanks.

 

Not having read the full story regarding your problems, I would suggest replacing all the coils. Mine threw misfire/restricted performance codes on two occasions, requiring two new coils.

 

Thanks Pete,

I will consider what you said in your post.