Uff da. Looks like I'll be doing the Weber conversion I was planning on anyway, just sooner than anticipated. Fortunately, AZ only sniffs for HC and CO, and only inspects for gas cap, cat, and secondary air injection, so NOx, EGR and carb type are not a concern.

Meanwhile, I need to pass emissions now to renew my past-due registration. Reckon I could just reinstall the diaphragm (for sealing purposes only) and cap-off the external vent barb, so the bowl only ever vents internally? That should solve the rich-running problem due to a malfunctioning external bowl-vent valve, no?