Nope, they never did. My truck is OBD-I - not -II - no catalytic converter monitors, nor O2 monitors.

Because it's a passenger vehicle with registered weight of around 5600 lbs, the answer was to manually change the weight code to >8500lbs GVWR and the machine would call for an idle-sniffer check. If they didn't manually change the weight code, it would call for an OBD-II check and fail.

If it was commercial, and the reg had the GVWR on it, it would automatically pick that up and call for an idle sniffer check.

Now, they don't even bother with the idle-sniffer, and it's just a safety check.