P0134 and Oxygen Sensor Heater monitor

Hi,
I have a question about the readiness of the Oxygen Sensor Heater (HO2) monitor:
Some weeks ago I had a P0134 (with a '96 Plymouth Voyager). The broken O2 sensor got replaced and after some drive cycles all of the monitors except the HO2 monitor were set to ready.
The last one set to Ready was the CAT monitor after a long drive on the highway.
Since I was due for emmission test I decided to go ahead and see what happens. With no error codes and all other monitors ready it looked not that bad.
But to my surprise the vehicle inspection report listed all monitors as ready. Even the HO2. To make sure the missing one didn't got ready on my way to the test station I checked again afterwards but the HO2 is still reported on my hand-scanner as NOT READY.

I was wonderng what needs to happen to get the HO2 to be ready and what is the logic of the emmission tests of the readiness? Can a depended monitor declared as ready if the 'master' one is ready? For example if both the oxygen and cat monitor are ready, the HO2 cannot be non-ready?

Im not really sure why you passed with an O2 monitor not ready. Sometimes cheaper scanners may show a monitor "not ready" when in fact the monitor is physically unavailable. For example,on a 4 cyl. fuel trim data may display that bank one is "closed loop" and bank 2 is "disabled". Bank 2 isn't disabled, it doesn't exist, and the scanner is translating info the best it can. Still, that is weird....Usually an O2 monitor doesn't take long to reset....but.....i don't know why. Maybe the tech passed it without looking closely...maybe your scanner is faulty?

Not available monitors gets displayed as N/A on my scanner and I could see the change from NOT READY to READY during the drive cycles for the others.
From this I thought to get some reliable data, but of course I will not compare this $50 (From-EBay-)Scanner with a fully equiped test station
My expectation was to see this one monitor as NOT READY but get a green light for passing. Its was the O2 heater monitor. The O2 monitor was READY.
The test was fully automated. The lane operator plugged in the connector and handed me over the result a minute later.

Thank you for your answer!

Here is a copy&paste of the result:

Test Results Test Type:
OBDII Prescribed Test: OBDII
Overall OBDII Results: PASS
Readiness Result: PASS
Fault Code Result: PASS
MIL Result: N/A
MIL Engine Off: PASS
MIL Engine On: PASS
Misfire: READY
Fuel System: READY
Comprehensive Component: READY
Catalyst: READY
Heated Catalyst: NOT SUPPORTED
Evaporative System: READY
Secondary Air System: NOT SUPPORTED
Air Conditioning System: NOT SUPPORTED
Oxygen Sensor: READY
Oxygen Sensor Heater: READY
EGR System: READY
MIL Commanded On: NO
Fault Codes:

Yeah, it's strange to me, because I've never had that happen. There's a glitch somewhere, but who knows where? Wish I had a good answer for you.

FYI:
This morning the HO2 monitor was set to ready!
I'm not sure what was the reason, but unlike the usual driving I made a longer drive on the highway. I check the monitors quite often because I am curious about the fact that the HO2 was not ready yet.
I think I never made the required drive cycle for the HO2 but today I did somehow. Looks like my code reader is working fine