[Chip Hutchinson]

Hi again.
I have more advice. I don't Know what you do for a living or where you work or what you have access to. Infra red thermography is a booming field. I have a level II certification. Here where I work, I do all the thermal imaging of our switchgear and electrical distribution, therefore I am allowed to use the IR camera and the company has let me take it home for personal use. If you have access to an IR camera or have a friend/relative that does, you can use the camera to find the cylinder(s) that are misfiring. The misfiring cylinders will have correspondingly lower exhaust manifold temperatures, and since your car misses at idle you could quickly determine which ones. After that, you would still not know why those particular cylinders are misfiring, but it would be a way to narrow the field a bit. For example. If the exhaust temperatures are consistent on each manifold, but one manifold is significantly different from the other, it may indicate a vacuum leak or out of spec O2 sensor for one bank. On the other hand if one port into one of the manifolds is cooler (or hotter) then it is narrowed down much further.
If you don't have access to an IR camera then all this info is just a waste of time, but on the off chance that you do have access I highly recommend the IR camera as a very powerful troubleshooting tool.

Chip.