Replaced coil pack (also swapped from another cylinder) and spark plug, but I still don't hear the crackling sound telling me there is a spark. What else could it be?

1999 117k miles. The shop just told me that it is the "igniter assembly". Does that sound right? They are charging me $550 to fix. Will this igniter assy fail for only one cylinder? The car still cranked up and started just fine. It just wasn't sending a spark to cyl#3.

but it could just faile on one.

its the part on top of the airbox, takes about 5 minutes to change, buy one yourself and install it yourself.

some of that 550 may be diag though which you would still have to pay.