what does it take to have ODB monitors prepared for emission test

It should happening every time you start the vehicle if it is OBDII. There my something wrong with your ECU.

I heard that it takes a several days or even ea week since the system is reset. Here I more curious about details.

Did you swap a chip in and out?

It's not uncommon for folks to chip a car, and try to reinstall the original right before a test.

you can reset it by the disconnecting the battery too.

There are parameters that are like that; adapt to the driving style,environment etc. But the emissions tests aren't one of them. The ECU is supposed to do an emissions test on each driving cycle and if a sensor is bad, throw a CEL code.

The problem is, it WAS reset and there have not been 'enough' or a 'proper' drive cycle(s) for the systems to clear a 'not ready' condition.

You might ask over at

Carl

There is a specific cycle of warming up, driving at certain speeds, stopping, etc. that has to be repeated a few times to get all the monitors ready.

In general, this cycles include city driving, highway driving and idling.

If your car does not have trouble codes but the monitors are not ready, it means that your car has not gone thru all the required conditions. There are some cars that are a pain in the nuts, some Nissan Maximas come to mind.

Good luck!

alf wrote:

I found this info that could be of use to you. You can also look for specific information on your model at the same website