Went to get the annual emissions test for my county here in Tennessee this morning. Inspector asked if I has disconnected the battery recently because the test equipment listed the following.....

OBD INSPECTION:
MONITORS NOT READY:
EVAPORATIVE SYSTEM
OXYGEN SENSOR

Cleaned battery terminals 5 days / ~110 miles before the test. Inspector couldn't provide any advise. Called Chevy Service and they said you need to go roughly 150 miles.

Went out and drove around town and some highway and went back to emissions test center with ~170 since removing and clearing the battery terminals. And, ...... same issue "MONITORS NOT READY".

Ideas about how far or what type of driving can make this happen sooner? Don't want to keep paying for inspections until they are "READY".

Appreciate the help.

 

What is eng. temp. if not up to 185/195 deg. might be why.

 

Maybe an issue if the engine was cold and running in "closed loop" mode, but if you've driven it, especially to the inspection station it will be up to operating temperature.

If a recheck after further driving produces the same result, I'd suspect an issue with the equipment being used by the inspector, of course they'll scream bloody murder when you suggest that....the state's stuff never breaks or is in error don't you know.

I would just drive the vehicle normally for a few days and reschedule the inspection, if the result is the same, suggest they have their equipment checked and go to another inspection station if you have one nearby.

OOPS! Almost forgot.... to the forum specman!

 

Appreciate the ideas.

Yes, it should have been up to temp for both inspections. I've seen on the info screen temps between 185 - 192 but didn't think to check it today.

I'll give a couple more days and record the temp when I go in there on Wednesday. Will update the post with results at that time.

BTW - this forum is fantastic. Just started using it recently to search old posted issues. There is almost always an answer already in here somewhere.

 

OK, went back this morning and the Emissions Inspection passed. No more "monitors not ready" messages.

I drove mixed highway and stop and go for a little over 300 miles and the water temp was 187 when I pulled up to test.

Chevrolet said 150 miles would be sufficient but that's not entirely accurate. It needs to be a mixture of driving, not just highway and somewhere more then 170 miles in my experience.

The lesson here? If you're going to do battery service, don't do it in close proximity to your next Emissions Test.

Thanks again for the ideas, this forum is great!

 

This is basically what your car needed:
http://www.obdii.com/drivecycle.html