How do I know when my car is ready for the emission test?

Question

I've recently had repairs done to fix an egr problem on my vehicle after which the check engine light was reset. I own an ODB II reader so I can check the codes. Will it give me a code that tells me its not yet ready for an emission test? or how can I tell when I've driven long enough to go in for the emission test. Thanks

From the first couple of answers I think I need to be more specific. I know it takes a certain amount of driving before the computer decides enough measurements have been made to allow it to pass the emissions test. My question was IS there any way I can tell from a readout on my ODB II reader that it has reached that point?

Answer 1

Does your reader show I/M status. That will tell you which test have passed.
Depends a little on the year model here in NC. You can have so many not ready codes and still pass. I can get most to pass in 5 to 10 miles.

Answer 2

The shop manual should list a pattern of driving that's done to calibrate the computer. If you don't see that, then 30-40 miles of mixed driving (city streets, idling, 45mph boulevards, freeway) is sure to do the trick.

Hurrah for the new generation of mechanics that isn't afraid of computer controlled engines!

Answer 3

A lot depends on what state you live in. I live in New York State, and every year when I get the mandatory inspection, the emmisions is part of the check up. If your have eco-concerns and can find a shop to do it cheaply, I would think it is money well spent.

Answer 4

in most cases its 7 drive cycles.