My emission system is still not ready, but I know what to do to complete the drive cycle. However, I can't do that until my O2 sensor monitor finally clicks to "ready"

What do I need to do to get this one to click over? I've put a LOT of miles on the car and a lot of starts. So far this one last system refuses to set.

There are no codes set or pending.

I put over 3.5 hours of driving on the car to get the Evap system to set last Friday. The secondary air system finally set today - after a presumed number of cold starts.

The O2 Monitor should have set with all that driving, but it's stubbornly doing nothing... Although the 02 sensor heater finished some time ago.

Any advice here? I'm guessing I need to let the car run for a *long* time. Can I let it idle? That's about the only thing I haven't tried so far.

Are you sure all readiness monitors need to be completed? Here in California I just coaxed my stepson's Mazda through a emissions test and the O2 monitor hadn't completed.

If the CEL isn't on and no emissions related codes are set you should be able to pass your inspection. I believe up to 2 of the readiness monitors can have an incomplete status.

My understanding is that the readiness portion of the inspection is in place to prevent people from just clearing codes right before a inspection.

Couldn't hurt to call your inspection station and ask their advice.

-Jed

Googling "readiness monitors MO" turned up this helpful link
http://www.dnr.missouri.gov/gatewayvip/docs/obdfactsheet.pdf