[dpaul]

I don't know what is causing the OP's smoking. However, I don't think it's likely that the breather heater is the culprit here.

The heater is external to the valve cover and the PCV valve. It's supposed to prevent freezing of condensate in the CCV hose, which could block the vent circuit. The recall is to address the issue of electrical short circuit and possible resultant fire. It's not that the heater in some way degrades and plugs up the vent circuit.

Just a suggestion, fix the obvious problems first, then worry about the headscratchers. You have persistent post-cat sensor codes so deal with them, don't just assume that post-cat sensor operation is unimportant or irrelevant to your other issues.

I do find it a little suspicious that you had all four sensors give errors at the same time. It's unusual for all to fail at the same time. It might be that they failed sequentially over time, reflecting an abysmal lack of attention from the previous owner but could also reflect a common electrical issue. All four sensor heaters receive a common B+ (through fuse F38 or maybe F04, the latter in the DME box in engine compartment), shared as George pointed out with the breather heater; could be a problem in that wiring.