The Dodge Company

Car computer data for Emissions testing?

So I was told by an emissions inspector that when a car fails emissions and repairs have been performed to potentially rectify the issues, the vehicle then needs to be driven several hundred miles so that he can get a proper reading from the built in computer.

If this is true, how far does a car need to be driven in order for him to get accurate information?

Also, will it appear that the car is working properly if this mythical several hundred miles has been driven or will it say that there is insufficient data and I need to keep on burning precious fuel till some unknown factor has been achieved to get an accurate result?

It is true that a disconnected battery will cause the car's computer to lose the data sets it collected from the o2 sensors when monitoring emissions. You then need to drive the car for a while to restore that data otherwise you'll fail an emissions tests for a 'not ready' result from your computer. The inspection facility will not be able to read you computer's data so they fail you.

How far, I don't know, your best bet is to just drive it around to work/school etc for at least a week or more then get it tested.

Once you drive the required distance or maybe needed speeds for a certain time period, it may also need the car to get to operating temperature to get the data, the car will allow the test and give the data either failing you for high emissions or not.

2008 Nissan Murano Car Computer (pc)