Checked the bank 2 (drivers side) exhaust backpressure. Less than 1 psi at idle and at 2000 rpm. The OTC backpressure gauge I have says that >1.25 psi at idle or >4.5 psi at 2500 rpm indicates a plugged cat. It doesn't appear to be a clogged cat by that standard however I am wondering of that is too low a pressure.

I think I'm going to replace all four coils on bank 2 and see what happens. I have read a number of forum posts where multiple coil failures have occurred.

I'd be happy to entertain any other ideas . . . . .