The car passed all the pollution requirments but the smog test guy failed it because of the computer saying that the car needed to be driven for a day and then brought back. He marked it as fail for the MIL/Check Engine Light.
He asked if the computer was reset recently or the battery disconnected of which neither has happened as of late.
If I take the car back will it pass since the car has been driven on the freeway a couple of times? Something just doesn’t quite make sense to me here.
Any help is greatly appreciated.
It’s possible you have a fuse blown preventing the ECM, or computer, from retaining it’s settings. It is also possible you have a battery problem.
To explain, the ECM is required to monitor the emissions from the car by Federal law. In order to properly monitor the emissions, the ECM collects data while the car runs under different conditions. Until it has enough data to satisfy these different conditions, the computer will tell the emissions station it is not ‘emissions ready’. If there is a problem with your car causing the computer to reset it’s memory, then the data is always getting wiped, and the car doesn’t become ‘emissions ready’.
A good shop can find and fix this problem. They also have a diagnostic scanner that will tell them if the car becomes ‘emissions ready’ before you take it back for your retest.
Take the car to Auto Zone, or other auto parts store, and ask them to use their scan tool. The scan tool will show the symbols which flash for the I/M system Monitors which are incomplete (not run, not ready).
Most often, the EVAP system monitor system isn’t ready (run, complete). EVAP is: the (fuel) EVAPoration Emissions control system (gas tank sealing, charcoal canister purging, etc.)