[Shotimes] Why does the CE light go on if the gas cap isn't tight on OBD II cars?

[BJamesjr@aol.com]

> When you went in for an emissions inspection they used
> to remove your gas cap and test the cap to see if it
> were working properly.  Since (at least here in GA)
> cars with OBDII supposedly know if your car is working
> right, all they have to do is plug into your cars OBDII
> port and the car will tell the examiner if it will pass.

In selected high-pollution areas here in Texas, they do both.  They plug into the OBDII port and interrogate the computer, AND they do some sort of pressure test on the gas cap.